With the recent interest in an original PB opening/latch mechanism, I thought you might want to see another variant.
This one is on a George Eister rifle.
Pictures used by permission!There are a few things of note (at least for me):
The push rod from the button in the toe appears to extend
through the upright part of the latch, similar to mechanism on the Frederick Sell in the other post, essentially locking it in place.
There is also a piece of metal, or staple, protruding into the opening, opposite the top of the latch (to the right of it in the picture) that serves to guide the catch from the lid into the proper position and prevent the lid from shifting sideways.
Also, as Jim Kibler mentioned in the other post, the wood remains and fills the space under the butt plate extension .
Finally, what surprised me is how frighteningly thin the remaining wood is on the cheek side of the opening. But as was pointed out to me, "It has lasted over 200 years."
Jeff