1937 Mauser

[Mac Cat]

Regardless, you have an interesting gun to explore.
The proofs on the right frame are very cool and the serial number is pretty cool - the "100" and matching "00". It's worth exploring further, even if it's not of collector value.

When you break down the gun, you will probably find more parts that are numbered. Even the grips sometimes have numbers inside of them.

Thanks for sharing your photos!