Hey!
I've got you 2 sources for your Kenmore vacuum-
Jimmy Martin (Rugsucker), he is going through his entire warehouse of vacuum cleaners, he's bound to have one.
2-The gentlemen in the vintage forum (Username: hlrayjr, see thread: "Final update") is selling his recently acquired hoard of vacuums, I saw that he has the power nozzle for this model kenmore, and where there's a powernozzle, there's bound to be the canister too!