I'm not fond of your spark plug lead, and the governor linkage seems to be missing in the pictures. Can you post a picture of the assembled engine? I'm glad it's now running well, but the best way to keep it doing that is to make it as similar as possible to the way it was when it left the Briggs factory. I understand you don't want to spend money on an old non-collectible engine, but I'm sure you do want reliability.
The genuine Briggs spark plug lead is very reliable - I once clamped one between the air cowl and the governor plate so hard that after a couple of mows it shorted the ignition to ground, but as soon as I put the wire back where it belonged, it was as good as new.
