I have not purchased parts from everyone (although sometimes it feels like it). The folks listed immediately below are folks I've done business with and had a good experience. Isetta folks tend to be good folks (but there's always that cracked egg in the dozen). No guarantees. There are not many folks that deal in Isetta parts and for most, it is a labor of love. If you deal in parts or have had a good experience with a restoration service unique to the Isetta, please let me know.

awaiting restoration...
Photo essay of cars needing tender loving care... submit photos!
book on isetta restoration
This book by john jensen is truly wonderful if you want to restore, or keep up, your isetta. highly recommended. He has sold out of the originals and now has hi-quality copies for sale for about 80 bucks. contact john here for more details and exact pricing. update Veloce Press is looking to publish an updated version of Jensen's classic. Stay tuned.
isetta factory repair manual. Great addition to your Isetta resource library
hans rothkegel
Ask hans for a copy of his well designed catalog that includes nearly every single part for the isetta. His prices are reasonable (including the shipping for larger orders), he accepts internet orders, and most items ship and arrive within several days even though his home base in is Germany. I've been very impressed.  
isetta parts from Isetta John!
Isetta Johns is the place to go to for used as well as new parts. good, fair prices. Isetta Johns is also very knowledgable about these little cars. A true fanatic. A legend in the Isetta-car culture. Isetta John rebuilds Isetta shocks and a much lower price than buying new ones. Isetta John is now the source for Isetta export model bumpers. Isetta John has bought out Bill Darland's inventory of parts.
isettas-r-us
Another good and plentiful source of new parts. good price for replacement windshields... Werner Schwark knows isettas! He does engine, tranny, and chaindrive rebuilds and a nice new catalog with just about ecerything you would need for your restoration. His homebase is out of Georgia.
bing agency int'l
If you need parts for your carb or a rebuild, go to these folks: the original manufacturer with an office in Omaha! They do a real, real nice job with your carb. Don't even think twice...
coker tires
you can get yer tires here if you'd like. I did. I got some nice whitewalls.
whitepost restorations
they do a wonderful job of resleeving isetta brake and wheel cylinders. just take off yours and send 'em in. They do the rest.
george blau
George has brand new 12 volt isetta regulators (which can also be used on Heinkels, BMW 600s and 700s, Messerschmitt Tiger 500s, NSUs and most cars using Dynastart starter/chargers) that are about half of what a Bosch costs. He also makes front windshields for isettas (in two colors! clear and automotive green). These also go for about half of what they cost from other sources. Send George an email for prices....
isetta club e.v.
If you can read German, you can order parts from the German Isetta club.

what to look for according to isetta john...
dave major has made a video "shopping for your first isetta" <view catalog>
one man's thought on price...
hemmings motor news
old cars weekly
alan's unusual autos

jim's microcars
bromley bubble: soap and spare isetta parts!
isetta online (parts from germany: gotta read german though)
some rubber parts (search BMW)
Isetta parts catalog on compact disc from BMW BMW has some parts, but I am told that they are very expensive (what else would you expect from BMW?)
tires for the isetta @ coker tire (search on 480x10)
performance parts...
german parts site

• Contact Richard at ProSource Glass - 877- 345-2800 for Isetta windshields.and tell him I sent you.

jc whitney more general car restoration stuff
karr rubber (no web page) 1.800.955.5277

technical resources:

paint chips for isetta (courtesy firemarshall bill)
isetta paint schemes

isetta rebuilding tools, videos, and stuff
another source for the workshop manual
roundel isetta articles search on isetta...

era plates for your car?
i found my plate on ebay search on <year> license plate <state>
insurance in case yer bubble bursts...
need a picnic basket for the back of your car?

chris's restoration
mary's isetta restoration
german restoration
my restoration...
bruce's restoration

spark plugs:

• Bosch W7AC
• NGK B6HS    
• NGK B7HS
• NGK B8HS
• CHAMPION L78C
• NGK 5110 B7HS
• Bosch W4AC was the original plug, but doesn't reportedly work well with modern fuels

battery:

• BMW motorcycle battery
• Yuasa Y60-N24AL-B, a 28 hour battery used in the Harely Davidson Buell models

coil:

• any 12 volt, VW from same year should work
  

chroming:

• Oak Harbor, WA (F&C Plating)  ~$1,200
• Art Brass in Seattle and it is $1000.00 and 10 weeks
• Speed & Sport, Specializing in triple show chrome, 404 Broadway, Houston, Texas 77012, (713)921-0235, 15-day service

tires:

• Deerstone 450 X 10 tires from Thailand (~$30)
• Coker 480x10 (~$80, whitewall)
• Nankang 480x10 (~$30) can buy from NTB! (National Tire and Battery)
• Michelins 145x10

fuel filter:

• 356 Porsche

shocks:

• NAPA , you can order part #94017
• if you don't go to NAPA, go to some other parts store
• the shock is the FRONT shock for the following vehicles:
      Chevy LUV truck pickup, 2WD 1972-1980
      Chevy LUV truck pickup, 4WD 1979-1982
      Isuzu Truck, pickup series 4WD 1983-1988
      Isuzu Truck, Trooper and Trooper 2- 1984-1986

tidbits on trailering the isetta:

• can use a 5' by 8' tilting trailer made by ISP with a 2,000 pound boat winches on the tounge to pull the car up on the trailer.
• do not put a car cover over the car when trailering. The wind will flap the cover around and mess up the paint job.
• the smallest trailer you can use is a 5' by 8' open trailer. A 5' by10' would be better for strapping purposes.
• can use a steel open bed single axle utility trailer with ramp
• a full ramp is a lot easier to use than boards or those adjustable ramps
• make sure you have your isetta strapped down properly, maybe using wheel bonnets.
• keep the hitch tight, keep the bearings greased, inspect the tires, and keep the air up. this is very important for the smaller 8" tires ( they tend to heat up and self destruct)
• keep your load centered left to right and the tongue weight positive (40 to 100 lbs).
• tie the isetta down by the axel in the front and rear
• do not tie the car down using the rear bumper!

other tidbits:

• fuel gage: can use a fuel gage that doubles as a gas cap made by John Deere for its riding mowers (via bill darland)
• installing seat belts: I used old non-inertial Daihatsu Cuore belts, the only ones I found light brown in our market and with a size more and less proportional to the Isetta. The anchorage points were both bolts which tie the body to the frame lying at the back of the seat. I chose the third anchorage point at the side, on the steel sheet that goes under the sliding window. I made a hole in this sheet and added a thick piece of iron of approx. 20 cm. long and 5 cm. wide, with another hole with a nut welded in the middle of it, in such a way that I formed a "sandwich" with the steel sheet between the iron support and the belt fixations. In that way, belt should pass by your left shoulder to engage the other side at the center of the seat. This is the best arrangement I managed to get. -Ernesto Parodi.
• Starting the isetta engine (with no regulator) - Hook the Negative terminal of the battery to the engine case anywhere. Connect the green wire from the coil (+) to the Positive side of the battery . This will now energize the coil. Now connect the Positive terminal of the Battery to the Starter Post. If you already have the wire connected to this, just connect it to the wire. This should cause the engine to crank. Once it starts, remove the Positive contact from the starter post. Do not crank for more than 15 seconds at a time. Don't leave the power connected to the coil when you are not trying to run the engine, you could overheat it and make a big mess. - Jim Janecek
• isetta trailers - Piccolo made them, but very rare (3-4 left). Reproductions around. Quicksilver trailers in a possible source. A german teardrop is another.