Mistake #1, since nobody pointed it out, and are not likely to, and it might be one of those things that bugs me, and nobody else:
I am surprised that I was able to use this lock on a Lehigh. This gun was a project where I had a lock and a barrel, and said to myself 'what can I make with this?' Without much more thought or study, I went ahead with a Lehigh. It was going to be a plain Jane gun, no carving, just a shooter.
When I started cruising the photos of Lehighs by different builders, I noticed, after my lock had been let in, that the locks were predominantly flat bottomed(no curvature to the plate), and quite long in proportion to their width. I had chosen a fat lock with banana. Not what you'd pick for the best Lehigh architecture.
That said, the shaping of the breech area was extra challenging, trying to shape the lock panels and wrist to Lehigh look with a chubby lock. A lot of compromise took place.
This is how I build a gun: start the gun, then figure out what I'm building, and THEN try to make the materials fit my idea. This is putting the cart before the horse building, I'm always bailing my self out.
T