I have a 90 TRX300FW in the shop now. Putting a starter, new front brakes, repaired the rear brakes and will do a service on it. It has taken over 3 weeks to get the parts I needed mainly the front brake cyclinders.
Glad you got things sorted out and the GT is running once again.
Not sure if you mean your shop, or someone else's shop. If you don't have a TRX Shop Manual, get one, the TRX is one of the most User Friendly Back Yard Mechanic ATV's ever made. Most of the parts you might need, you can get from a Dealer here, I can give you the link or do what I do, go Ebay and go internet, Used Cycle shops, and other research will get you parts lots faster and a heck of lot cheaper. I took a Saturday, just sit back at the computer made a list of all the parts I needed, Most either came from Kentucky or NC and I got everything I needed in 3 to 4 days after ordering.
The hardest thing I tried to get was a tool box lid with the tail light assembly and even a used one was well priced. Motor parts, Carburetor parts, break parts and even engine parts are easier to find than plastic. That said, EBAY and a couple of other places is by far your best bet for fast parts.
The push on fender screw locks, well I got those out of Hong Kong for a Mazada Car! LOL, 6 to 9 bucks a pop for one at a cycle shop, I got 25 for $4.95 and this are nicer than the originals, they have the positive driver remove, looks like a screw instead of a pull tab.
All my top engine parts, I get from Wilkes Ridge Cycle here in NC.
Oil Filters, K&N, Air Filters, Moose Racing, Carb kits, Moose Racing, Break Parts, Either Wilkes Ridge or Ebay, got all the parts, including rebuilds for the cylinders from Ebay, for about $50 bucks, Rear End parts, All Balls Gasket and Bearing kits, for around $60 bucks. That includes front and rear...
Starters, I get the kits, brushes and all, and have cleaned and if the armature needs turning local shop. Or you can pick up a used starter really cheap, rebuild it and sit it on the shelf, then if you need a new know there you go. I discovered on my last 4x4 ATV that starters are over priced and the labor costs is well over board what they should be...most of it you can do yourself easy.
Assuming of course you don't do it already but if you do, well then you know the TRX is the Best Honda they ever made and the easiest to work on. Shop Manual is worth its weight and http://www.cheapcycleparts.com/
has online Parts Diagrams that is worth it's weight in gold! They have a good selection of parts too!
If you need some other links let me know..I got some from back in the 90's when I had my last atv! LOL