Doug
Sadly these days there is nothing that will 100% assure originality of any dagger other than experience in hand. Confirm the manufacturer is Weyersberg and that the grip insignia is correct and properly affixed, check the chain clip by comparison to others -check my website or Johnson/Wittman/Hogle ,and if all looks to be ok post copious pics here. The best guys in the hobby are here and you'll get the best advice available
Good luck
Paul.


FUR EHR' UND PFLICHT BIS HERZ UND KLINGE BRICHT