The 5906 pictured on the website appears to be a PC DPA prefix 5906. I doubt that is what they have for sale given their asking price and the claim that they were made in 2009.
Houlton laser etched the markings on the 3rd gens they produced.
IMO that is a lot of money they are asking for a vanilla 5906. NIB or not. Caveat emptor!
Regards 18DAI