In the 1980s I went TDY to Redstone Arsenal to attend a two week computer corse. Naturally, during the middle weekend I cruised the gun stores, hock shops, etc, in Huntsville. I found one place, Bubba's Pistol Parlor; they didn't have all that many pistols but they had hundreds of shotguns; apparently the deer season was shotgun only. I was at one end of the counter, while the salesman chatted with a friend at the other. I heard him say "Here's Kaiser Bill's pistol" as he passed an obviously European revolver across the counter. I wasn't very interested undil the customer cocked it and the mainspring guide stuck out the front of the frame. Then I had trouble controlling my bladder function. After a lot of hot air, I got it for $150.
It's a solid frame Mauser Zig-Zag revolver. The hghest serial number known is 65 so they didn't make very many. The hinged frame zig zags go up to over 3000 and they're considered a very rare find when you come upon one. For several years I beat the bushes for zig zag data and only came on six other solid frames, and they're all in the 10.4mm (DWM #7) caliber. My revolver is a 9mm (DWM #6), and is serial number 4. I've never encountered another one, and believe me, I've searched. What's it worth? I don't know, but probably whatever someone wants to pay for a unique example of the zig zag line.