Sold for $1,610 in the February 2020 Sport & Collectors auction.
Ross Rudd was born in Toronto in 1915, but his family moved to Springfield Massachusetts in 1917, and he would grow up there. Interested in guns and gun design from an early age, Rudd went to work for Savage in 1940, where he was involved in Lee Enfield production and the simplification of the Thompson SMG. In the early 1970s, he formed his own company to produce a pistol he designed using a clever delayed blowback design. He also adapted the system to a rifle, and it is his prototype AR-180-based rifle that we are looking at today.
While the mechanical system seems sound, and his prototype pistol appears to have run well, Rudd was unable to find a financial backer for the project, and neither the rifle nor pistol ever went into production.
You can see Rudd himself explaining his pistol here: https://youtu.be/7lAxVYYhACM
And his patent here: https://patents.google.com/patent/US3998126A/