Yes, Mr McCubbin was a major collector of Old West photos and other items. As I understand it, he and BBB bought True West magazine together. The auction took place in 2019. I attended the photo portion and thought it was very interesting. Btw, photos and their authenticity are occasionally discussed on the Wild West Collectors page on Facebook, which is operated by David de Haas.
Thanks for pointing it out. So is the author Robert McCubbin an old west photography specialist? I think I saw an auction of some sort where some of his photo collection was being sold…