It turns out that a lot of the Kirby vacuum cleaners are part of a series called "generations," and this Arm and Hammer bag fits them all including ours:
https://www.walmart.com/ip/Arm-Hammer-Kirby-Premium-Bag/20525154
www.venturavacuumrepair.com/kirby-vacuums/history-of-kirby-vacuums/
