I would be interested to know too, as I came across similar pieces on a US site and quite fancied one.

I'm no legal expert but my guess is it would be ok, as in its current state it's not capable of being fired and is therefore a non-firing replica. It never has been capable of firing therefore it's not a deactivated firearm. The original firearm of which it's a replica was designed before 1873 (think that's the date) so it's not a RIF (realistic imitation firearm) under the VCRA.