This gun would have been proofed 1887 or later due to two reasons, the word "Choke" rather than "Not For Ball" & also the 12/C chamber mark. I do not believe it can be said with absolute certainty this gun was not proofed between 1896 & 1904 as the Nitro Proof was still an option during that period. While it may well be true that most guns submitted for proof during those years received it, it is also true that "Not All" did.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra