IF it is an antique, then you are correct. IF, however, it is a modern replica, even though it is a miniature, and it is drilled through to the chamber, it is a Section 1 firearm, like the one just made by the OP's buddy. Navy Arms made a .69cal 1/5th scale replica of the ACW Napoleon cannon as a kit and as a finished item - both as a Section 1 firearm with a drilled breech, and as a rather large but impressive desktop ornament.
One could be bought with mere money, the other only on production of mere money and a valid FAC.
tac