Hello, everyone from Old Westerner.

I'm writing for info about a Colt 12 gauge S x S, Model 1878, DOM 1881. This a project gun. Does anybody have a schematic? Or a link to where one is out there on the Internet? Did this model originally have firing pin springs to retract the pins into the receiver? Barrel release lever is loose. Did it originally have a return spring? Maybe a coil spring under the lever screw?

May have more questions later but any help or leads now would be greatly appreciated! Thanks!