As for weps with Roman numerals research seems to point to Confederate State rework marks, where captured weapons were reworked at the larger workshops of the CS before being reissued. I have an Austrian 29.5" Kammer-Karabiner relic dug at Gettysburg back in 47' that has XVll scratched or engraved on several parts including the Barrel and inside lock. Though the Union purchased 10,000 they were no longer used by Federal troops that late in the war so believe this little carbine was lost by a Confederate Cavalryman.
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