Did you try Hesco?  Sometimes they have what I need for my older Eurekas when nobody else does.  I see from your profile that you've listed a certain Eureka model, 1759D.  I couldn't find that specific model, but I did find a schematic for models which seem to be similar to that one.  Maybe that would be a good place for you to start.

--Bill W.

I just read your other post ... something about the Eureka being a 1270 series machine?  Here's a schematic from Hesco for that ...