I really love that frame!!
As you have now revealed the decals, I am pretty sure that you have a 1994 model. 1993 models had plain coloured decals, 1995 decals had rugged edges. Your decals show this fire-pattern - similiar to many other 1994 decal styles. In addition, the 1995 model already misses the replacable rear derailleur hanger.
Personally, I don't find the XT 737 visually that appealing. You lovely frame deserves the best and something in shiny silver. Go for XTR 900. You will get decent money for you NOS XT 737 stuff.
This is how you bike will look with XTR 900, black GT Flip Flop III ahead stem, silver post and black saddle. Lovely....
If you decide to go Non-Shimano, I would opt for a silver Campagnolo group.
By the way: if you ever decide, to let one of those GT bottles go: I would love one!