Other difference between euroarms and armisport is the barrel, armisport made the barrel making a forged upset were is machined the nipple bolt, and the breech is close by a threaded plug with the tang, euroarms made barrel in three pieces, the tang, the section with nipple , and the barrel, so with a carefully inspection you can see where the part are screwed, not easy to see because are machined toghether after screwing.
If the barrel doesn't show any proof mark or serial number may be this musket is "defarbed", you buy it new or used?
ciao
Rusty