There's a rather rare Armi San Marco .44 Dragoon Revolving carbine with an 18 inch barrel and folding sight.
They can occasionally be found for sale on Gunbroker.
And the 51 carbine is a Pietta, marketed as a Schneider & Glassick revolving carbine. Basically a 51 Navy with a half fluted cylinder.
I believe that's a .36.
https://www.huntingnet.com/forum/att...p;d=1555861499
https://www.huntingnet.com/forum/att...p;d=1555861499
https://www.huntingnet.com/forum/att...p;d=1555861499
https://www.huntingnet.com/forum/att...p;d=1555861499
