Daryl, the gun I showed pictures of above is a nominal Edgar Perks made in the forties. It has chopper lump barrels like yours as well. No idea who made that one.

The other similarly configured gun I own is a Leech & Sons made by G&S Holloway. I have the records and original catalog entry on that one. No reference to being a self opener in either. Here are a couple pics of the action and locks on that one. Like I said, similarly configured.


[Linked Image from i.imgur.com]

[Linked Image from i.imgur.com]