Pete
I've got 3 of them from my travels. They were made around the 1910 era according to the locals. Mine are very plane jane by comparison to what you have. All 3 have the rifle like sites too.

The 20 ga and 28ga both have 34" bbls.
The 9mm shotgun has a much nicer stock w/ checkering but still, nothing like that. All work on the same principle/action as the Murata rifles. They were just scaled up/down.

Dan

Dan