Jim,
Just my $.02, but I have a suggestion for each problem. The too short frames tubes and fittings shout find a home with a short squatty experienced (as in old timer) framebuilder who would fing\d something creative to do with it. A nice set of wind chimes comes to mind, ;-).
If I were in your position I'd replace the seat tube with a metric tube (just within the past week or so someone on either the framebuilders list or CR mentioned they had lots of standard and metric tubes, Vitus or something I think) that isn't 753. Then I'd find some thinwall double taper 16mm (or 14mm if you want) seat stays to use. I'm sure I have some nice light stays you can use. I probably have single taper 16mm thinwall stays as well. Let me know what you decide to do.
Regardless, good luck.
Brian Baylis
La Mesa, CA