Great discussion and good suggestions! Now I am not going to do anything too quickly or without a great deal of consideration. The gun was reproofed in 2009 and is reverse choked ("grouse choked"):
PROOF: Right: 728 Left: 728
READING: Right: 729 Left: 730
MWT: Right: 22 Left: 26
CHOKE: Right: 0.015 Left: 0.005
So I was not aware that adding metal to end of the barrel would take the gun out of proof. I might like to bring the the left barrel out to 0.025. Would it be visible (a line around the end of the barrel like a screw in choke)?