I removed the head for inspection last night and didn't see anything glaring out at me.
I filled the head chambers with gas and let them sit....no leaks after an hour.
I reversed and filled the intake and then the exhaust ports with gas and let them sit...still no leaks after an hour.
I put a bit of oil into each cylinder and didn't detect that #3 was leaking. And certainly not any more than the other cylinders.
So now I'm stumped...perhaps a leaking head gasket? As per my previous entries, I was concerned that I had to remove and re-installed the head gasket so many times when I was fly-cutting the pistons.
The only thing different that I noticed about #3 was that the piston was much cleaner (and much easier to clean), than the other pistons. The carbon deposits basically wiped off while the other pistons were much more hardened. In fact, I noticed that the stuff on top of the #3 piston was a little gummy where #1, #2, and #4 were more like the standard piston top.
I'll post pics up later tonight.