Yep... I don't know.
It has known running issues, ("needs a tune up, and the jetting is off") and no trailer. Honestly... I don't know if it's worth it. I guess I would have to go see it up close.
My questions would be...
1) What oil are you burning? (needs to be full synthetic API-TC)
2) who shaved the head, and what did they do to it?
3) Who did the motor rebuild, and is there still a warranty?
3a) was it a full rebuild, or just a top-end? (if it was just a top, I don't think I would buy it since the crank will be tired)
After that... I would check the compression myself, and look for any other mods. Also, I would pop off the RAVE caps and see if they move free.
Now... boring an engine 0.010" over shouldn't change the jetting at all. So... ask him why he thinks the jet's need to be changed.
Also... look for the gray Tempo fuel lines. If they are still on there... that's probably why it's not running right.