Not sure why I didn't do this in the first place. Here are some screen grabs of the Strangest Air gun
Brass castings look very nice. Just looks like it was manufactured by a real gunmakers. Looks more English to me than German, but, hard to say. Such a weapon would be perfectly acceptable in England but would be restricted in Germany and most other Continental countries in the 1800s.
German, 19th century. brass running with mantle from Spanish tube, including black pre-painted Kit System. Unscrewable, large reservoir with punzierter leather sleeve. Old-age and wear. Length
I wonder if it's bamboo lined with brass barrel? However bamboo would be fine for some projectiles and pressures, ala blow guns. It almost looks like some script on end of female fitting in lower left picture?
To me it has an oriental look like the Philippines or somesuch because of carving and brass work and use of bamboo.
Walking-stick air-guns can be found with a faux bamboo finish, for the simple reason that the intent was for the air gun to look like a walking stick and walking sticks were often made of bamboo.
It looks to me that this strange fellow sits right between the late British pneumatics circa 1800-1850 and the Walking-stick air-guns that came to dominate after 1850. The air tank looks like it goes with a late British pneumatic. The trigger, exhaust valve assembly has the same trigger and cocking arrangement found on a walking-stick air-gun and the barrel is made to look like a walking-stick. It's only a short step from here to a full blown walking-stick air-gun.
Bet there might even be a name to be seen on the internal works, like often seen on the walking-stick air-guns.