>Obviously a replica
Replicating a Hurricane costs a stupendous amount of money and then isn't worth as much as the genuine article. Having tank stripes produced with "BSA" on them only adds to the stupendous amount while highlighting even more that it isn't "genuine".
Otoh, there were a very small handful of pre-production bikes made with "BSA" on the stripes, Vetter prototyped the Hurricane on a Rocket 3, production Hurricanes would've been BSA is BSA hadn't gone tits-up.
If it really is a "replica", there will be a very interesting 'back story'. Otoh, it might be one of the pre-production prototypes. Graham will get a lot of questions similar to the above; PM me the engine and frame number?