Bob,
Can't help with the T tops, but I do know someone that is soon to be selling a 100% rust free shell. Firebaron90 (Joe D'Ambrosio) has an 89 Daytona Shelby, blue/silver package color. It's a hard top, and it's a PA car (Philly area), but it has NO rust (at least zero as of March of this year, last time I was under it). I do mean zero rust, it's amazing for this area. Never been in an accident, and has good glass, and at most a few dings (nothing that I would consider a "dent"). It will need new paint, as the paint is starting to do that "bleach" look on the roof.
Joe is looking to take all the work he did (engine, trans, etc), and put it into a Lebaron or Shadow. Which will leave a rust free shell. He *may* sell the car outright (ready to drive), not sure if you want what he has (T2 with some *nice* go fast goodies in the engine buildup, auto trans with reverse manual valve body). Both the engine and trans were worked on by Brian Slowe. Interior is also VERY clean, I think the only issue is a sagging headliner. He also has a whole spare front fascia to go with it (correct blue color).
If you are really interested, PM me and I will give you his phone number (he just bought a house and may not be on the forum a lot these days).