Over the last year there has been two threads on this boat/design, here
You may find some answers to your questions there, particularly relating to your last question.
Your first question re. Lehman engine
: I found them good reliable engines, running at low revs, using relatively little fuel
, easy to work
on, and the last time I worked on one (8-10 years ago), spares were still available. If well maintained, should be still OK.
Good luck with your boat hunting!
Just checking....... is it this one?
Used Robert Perry Cutter 47 for Sale | Yachts For Sale | Yachthub
This one has been on the market for at least 12 months, maybe nearly 2 years, and the asking price
has dropped from near to $200k to the new price