Thanks. System makes sense to this old barrel-gripper. Who needs furniture behind? But slow loaders for sure. Was wondering why the checkering went back underneath almost to the buttplate and can see how it would help hold the stock close to the body when reloading.

I'm stopping the exploration till I find a proper turnscrew. My three dozen are mostly junk. Can't see well enough to grind one to fit. The screw heads are widened very slightly, but retain fit and finish. Certainly a sign barrel removal was infrequent.

A couple more notes. bbls 30.5" and retain nearly all original blue finish.
Both hammers hold half and full cock.