I was able to find a No 151 the appears to be in very good shape. It has a red/orange cap and the No. 151 cast on the back is plain, so it's a type 5 or type 6. I might have preferred an earlier model but it cost me $13.50, so I'm out less than a new Stanley that I know is roughly cast and poorly machined.
The label on the plane body reads made in England which is encouraging but it's still possible the body was cast in China or India and may not be machined as well. Maybe it'll be nice right off or maybe I'll need to do some work. I'll find out next week when it arrives.
Thanks for all the tips and advice.
-- Dan Rode
"We are what we repeatedly do. Excellence, then, is not an act, but a habit." - Aristotle