Help needed about a Spencer carbine

[razorback1010]

I've just found an original Spencer carbine, and before ordering a CF breechblock for it I'd like to find as many infos as possible about it.
First of all, it seems unfired. My guess is that carbine is one of the 44,000 Spencers shipped to France in 1870 and which mostly stayed in army arsenals for lack of ammunitions.
The breechblock, firing pin and the inside of the barrel are factory new. The serial number is 32135, the marking on the top of the receiver is "spencer repeating rifle co boston mass" the third line is mostly erased and you just guess "pat march...". On the right side of the receiver it is stamped "137". on the left side of the barrel, near the receiver there's a very small "p". There's a bigger "p" followed by "s2" on top of the barrel under the front-stock ring. The loading lever has a "m" stamped on the right side and under the stock, the wood is stamped with a clear "F". That's for all the markings I've found.
Subsidiary question is : how to determine the caliber of that carbine ? 56-50, 56-52, 56-56 ?

 

[rusty from italy]

Made a modeling of the breech with cerrosafe or pure sulfur, then you look for the correct drawings of the cartridges and take some measure with the caliper!
ciao
Rusty

 

[arcticap]

It sounds like a great find. Where did you find it, a gunshop or a private collection?
Where are you going to order the CF breechblock from?
Maybe if you send it to them they can determine which caliber it is for you?

 

[razorback1010]

It's coming from a private collection and I'll order the CF block from Dixie I think. I can't send the complete gun because clearing the customs both ways would be horribly expensive.
I'll use some cerrosafe to mold the chamber and guess the caliber from the result. I'll post pictures as soon as I'll have the time to do it.