While I read that, it would have been illegal in both Belgium and Britain. Wirnsberger describes the penalty for trying to pass of a foreign barrel as British as 20 Pound sterling, a huge amount in the 19th early 20th century (in excess of the gun's value), and that Belgium marks were sufficient in the UK to sell the gun without reproof. So yes, the chance for a complete fake exists, maybe for sale overseas as a high-grade gun, but at least I don't see the gun as being so bad and so obviously fake that that would be my first assumption.
I used to love being able to hit hard at 1000 yards. As I get older I find hitting a mini ram at 200 yards with the 22 oddly more satisfying.