After Sweden’s Electrolux bought Eureka in 1974, they started to sell 120-volt versions of some of their European canister vacs in North America. Some were rebranded as Eureka, others were rebranded as Sanitaire. Along with Eureka, Electrolux owned both AEG’s vacuum division and the Progress vacuum company - both based in Germany. They also owned the Volta vacuum company - also in Sweden.
So it appears that North Americans were offered Eurekas made by Progress and Volta, and Sanitaires made by AEG. I would bet that you could find your vintage Sanitaire branded as AEG somewhere on the web.