Toby,all the parts seem the same. I thought that with the barrels down the tension on the spring helped lift the barrels up,when the barrels lifted high enough the springs were no longer under pressure so the little lugs bearing down on the cams needed less muscle to bend the springs. Not knowing this was the "wrist-breaker" patent I beleived what I was told when I bought the gun,some years ago.
So,if this is the same lock work as the sidelock Lancaster with the "lamb chop" lockplates,what is behind those plates? Would you have a picture of that to post?
Dustin,my gun dates to 1886 with no other info available. I don't know how to pull the stock,but it sure looks like Toby's pict.