There's an unusual vacuum on eBay just now - it looks like a Sanitaire, but it's marked as a Silver King. Now, as far as I knew, Silver King only ever made the well-known canister, plus the strange-ish Silver Knight swiveltop.
Is this a Eureka/Sanitaire that's private labeled as a Silver King, or did they really make a Eureka workalike for a while?
Eureka has made several vacuums that were badged with other names. I actually had one of these, and sold it to a fellow collector a while back at a convention. Nice vacuum, and has the ESP motor I believe.