Don, if Larry doesn't have the time or inclination to fix a water pump, a naked project is well beyond. Besides, the only ones I've seen done were on crash damaged bikes where there wasn't much choice.
I for one would hate to see it done to a perfectly intact ST. It kind of reminds me of taking FJ1200 engines and putting them in midgets, or Merlin aircraft engines into hydroplanes. Yeah, it can be done but it ain't right...
Larry, a 22 year old bike is going to have issues. You can just about count on something. Yes, air cooled bikes don't have the issues of water cooled bikes, but I'd never go back to my FJ1200 after my ST1300. Just enjoy your ST after having it repaired, and if you stop enjoying it then maybe it's time to move it to someone who will. It's not like you're married to it.
BTW, I think you mentioned you had the carbs off. Did you get a look at those pot metal coolant elbows in the Vee? They've been know to corrode and leak, and it would have been a good time to address them if they are showing signs.