According to Wirnsberger it was an accidental mis-wording of the law which did away with the obligatory proof in 1885, & thus made it voluntarily. It seems though the French went merrily along in continuing to have their guns proofed. the Crown/PT was a smokeless proof performed with Powder T which was introduced about 1901, at least after 1900. I do not find any reference to those Crown/V marks in French proof either. The other marks would tend to indicate proof from 1901-1923.

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