I love single shot rifles, but also single shot pistols and that's a pretty neat one! Not sure I've ever seen one like it, but I bet it will be a fun shooter!
I've got a couple Remington Model 1891 Target pistols, both built by famous gun and barrel makers. One is by Arthur Hubalek of New York City, and the other by HM Pope. The Hubalek is .22LR Hubalek barrel and has a highly modified grip frame to make the grip larger, plus a lightened hammer, and trigger work. The Pope has a Pope barrel that is threaded for a silencer for indoor matches. Also has a lightened hammer, trigger work. over travel adjustment screw, and original grips.
Pope above, and Hubalek below:

[Linked Image from i.imgur.com]