My 1991 GT Tequesta that I acquired for $15 off CL last month. It was covered with dried mud and grease and appeared to have been left outdoors for some time. Tires were dry-rotted, seat cracked, dork disc yellowed from UV. The BB had play, so did one pedal, and the headset was only finger tight.

BEFORE:



Tear-down revealed the front Suntour hub had pitted cones. The rear Suntour freehub was OK, but both rims had sidewall wear. So, taking T-Mar's advice, I substituted a set of Shimano 7-speed wheels I had with low mileage. It took some fine tuning, but I managed to get the Accushift gear to work with the Shimano HG 13-30t cassette. Other changes include a new KMC Z50 chain, a new saddle, swapping in a Suntour X1 FD for the stock XCE in order to match the X1 RD, replacing the stock Cr-Mo GT painted stem (150mm) for a shorter 95mm Kalloy model from my parts bin. Too bad, I like the paint matched stock stem. (Should anyone have a shorter one, PM me.)
I did change the front brakes for a modern upgrade...the Dia Compe XCE cantis came off and a new Nashbar DeLuxe V-brake went on. This required swapping the XCE levers for a pair of Dia Compe V-brake levers. The rest is stock equipment that I overhauled and re-lubed.

AFTER: