Like Rod, I've been having thoughts about a compressor. An air hose would be a handy thing to have, and train horns live in the back of my mind. My misgiving about a belt-drive is that I already have the longer belt to accommodate the vacuum pump on the Jake. I'm not sure that If I wanted a belt drive compressor that I'd have any assurance of being able to find a new belt to fit. (I'd sure want to keep a spare, or maybe even two, behind the seat if I were to find a fit. )
In looking around, it SEEMS that York's (I think I've got that right) rig might fit exactly in place of the alternator (thus no need for a specialized belt) and relays power to the alternator. Do I understand that right?
So as not to hijack the thread entirely, it seems I might be thinking too hard on all of this and will sit back and watch the discussion of the pros and cons of 12v and belt-drive pumps.