20 Bore Pinfire Howdah Pistol

I also have a 20 bore Pinfire Howdah Pistol ex India.
Well worn with single trigger and odd opening action by pulling back the front of the trigger guard. I have not seen this before and there must be a patent somewhere?.

Barrels are smooth bored with 50mm chambers. 8" or 204mm barrel length.
Only marked 102 inside frame and F 102 under barrels.
Brass butt with lanyard ring. Used from a Howdah I was told.