Many years ago, my business partner and I purchased a ml rifle from the US. It was reported to be a Marston, Toronto flintlock halfstock hunting rifle. Canadianicon made flintlock rifles are essentially unknown. It was not inexpensive. This was long before things like instant internet photos. The snapshots we received simply did not show detail. The rifle was a Marston, alright, but it had been fitted with a "Maslin" reproduction flintlock. The seller really did not know that the lock was modern, and had replaced the original percussion lock. He took the rifle back, and refunded our money; we were out the shipping, of course.
When established dealers use terms like "100% original", or in "excellent condition", and these terms are obviously and foolishly incorrect, the only conclusion is that the dealers' ethics are questionable.