WOW- H1, No Worries, thanks for all the info! I just emailed dad the links. I'll let you know when he signs up. We were running errands today and looked a few places for a Haynes or Clymers manual- couldn't find one, but I'll check a few dealers tomorrow.
The guy he's getting it from doesn't seem to know much about it. Good guy, but it sounds like he got some misinformation. He says he cleaned/rebuilt the carbs, and that it was run on the street not too long ago. Problem is, he said it's a four-stroke, and it sounds like the carbs are all out of whack, and the petcock may leak. Unfortunately, I haven't seen the thing firsthand yet. Apparently, the title only says it's a 1975 Kawasaki 500. I've told dad the first thing we need to do is replace the tubes, tires, and brake lines, and rebuild/synch the carbs.
I'm looking forward to riding this thing. It'll mostly be used as a commuter, so that 78mpg sounds great, and the 60hp and 42ft-lbs sounds frightening with skinny tires and old components.