Greetigs My Good Mad Miles
you have hit a jackpot there alright.
i am sure others will comment on your highly desirable Red9 Mauser C96.
The colt revolver #173549 puts it at
Year of Manufacture 1897, Model SINGLE ACTION ARMY
as others have related, getting it "lettered" by Colt would be a great idea, it usually costs $100 to $200 USD
you can start here
https://coltarchives.com/https://coltarchives.com/archive-letter-infohttps://coltarchives.com/orders-%26-pricinghowever, it is possible that Colt might not have any records on your pistol, please see this auction site as an example
https://www.ancestryguns.com/shop/early-1873-mfr-antique-colt-45-single-action-army-revolver-ivory-nickel-saa-rare-1st-year-4-digit-serial-number-saa-in-45-colt/
The Remington revolver looks like the real deal, the 1863 New Model Army (often called the Mod 1858), the serial number 33250 puts it in the batch (serials 23000 to 6800 )
shipped in 1863.
your "1858" conversion is a classic "thin plate" conversion, in which a thin steel plate is dovetailed or otherwise attched at the breech section of the frame,
and the cylinder is machined down at the rear to accept a thick cylinderical extension usually attached by brazing or silver solder, since
modern welding techniques were not yet developed, at which point both the original cylinder and extesion were drilled, reamed, and chambered for the
desired cartridge. The first factory conversions were usually .46 Remington, but non-factory conversions could be anything in the .44 heeled cartridges
on up. A chamber casting would tell you.
Can you possibley post a photo of the barrel engraving, the ser number and the numbers on the grip frame under the wooden grips?
If you get a chance to go visit the barn again, we would all LOVE to see photos of the stuff there!
I will see what I can dig up on your pinfire later
yhs
prof marvel