Had a chance to put a few rounds through one of these today
It's marked 'Lux' and 'Made in Germany' on the barrel, and chambered for .22lr. Just in front of the hammer on the left side of the frame is a spring-loaded latch, push to the right and the barrel tips up. The extractor is not spring-loaded, as the barrel tips up a link pushes it to the rear. Front sight is a post with bead on top in a hood, the rear has a deep, wide 'U' with a much smaller one at bottom, just right for the bead. Hammer has half-cock and cocked positions.
About the only information on the auction was "The receiver is alloy
construction, as is the outer sleeve of the barrel (inner, steel sleeve
construction)." It was light, so the receiver and barrel body being some non-steel alloy fits. Barrel about 8" long.
How'd it shoot? Quite nicely. The hammer spring quite strong, the trigger a bit heavy but broke cleanly. I was only able to put about fifteen rounds through it, and it was fun. Hammer at half-cock; unlock and tip up barrel; insert cartridge; close & lock; hammer to full cock, aim, and fire. With a two-hand hold it held pretty tight groups when you did it right, one-handed more difficult. The thing is light enough that there's no weight to damp movement, so if you don't do everything just right, you'd pull the shot off a bit. I'd love to have the chance to put this thing on a rest and try it again.
They're apparently somewhat rare, as I found none on auction or sale sites, and only two old auctions for them. A neat little piece, friend of mine looked at the pictures and called it a parlor pistol. Don't know about that, but it was nice to make its acquaintance.