Thanks for all the feedback. I've found a like new Nashbar touring frame in 58cm for a decent price. I may have a buyer for the Trek 750 frameset which will greatly offset my the purchase of the Nashbar frame.

I'm confident I will be happier with this frame than a vintage frame given the rear dropout spacing, wider clearance for tires and fenders, and the potentially less worry-free aluminum frame for foul-weather riding (surface rust, though harmless, gives me anxiety).

I went with the 58 rather than 60 because of the unusually long top tube on the larger sized frames. At 59.5 cm, even the 58 cm frame is on the long side for me.

Any suggestions on the shortest advisable stem length? I'm looking for the greatest rise I can find, but I don't want to go so short that I compromise steering stability.

I'll post pics when I get it built up.