Excellent info here-to me the Bison machines were sort of a mysterey.The last I had heard of them-they were started by a former Kirby employee as stated.Would love to have the two models-they are kinda cool looking.And remind me of the "G" series Kirby machines built today-love the variable speed feature-too bad Kirby doesn't use it when a Kirby is in canister mode-that shouldn't be hard for them to do.Would be useful!!and Give Miele a good run for the money-Miele is famous for the variable speed on their canister machines-it can be helpful.also love the Big "Bison" symbol on the front of the "Bison" factory-yes I have seen the Bison he has spoken about when I lived in South Dakota.Quite an animal-and the meat is so delicious and good for you-better than beef.