If all that is lacking to prove authenticity is photographs of such daggers in wear, that could be easily solved. Assuming the "Big Boys" are all conspiring to sell these variations for big buck over the last 30 years, why would they not invest a few hundred dollars to have period photographs "Enhanced". A little photoshopping would definitely boost sales.
I have to be honest, I never owned, sold or traded one of these daggers, so I have no vested interest.