Thank you all for the kind comments! Indeed, a parts donor did resurrect the 37. Sadly for the Duplex 53, the belt pulley was broken off the fan shaft. That's the second one like that I've seen. I may find a donor armature at some point.
You bought the duplex from yelpavac. They have good items there shipping gets me.
Is the shaft part of the fan or is it built into the vacuum. I don't here any of these fine machines.
Nice trio.
Les