Since this is a Class A, the HVAC (Heater Ventilation Air Conditioning) came from a third party, perhaps Evans Tempcon. They may or may not have used a Blower Motor like one in a popular vehicle from Ford GM or Chrysler.
See if you can find the HVAC cabinet and remove the Motor/Blower assembly. Then start out at the auto supply and see if they can match it up for you. Here are some pix of Evans Tempcon's repair parts.
Pix HereCars and light trucks typically use a setup similar to this one

But it may have a double shaft motor like this one, and those are less common in the rest of the automotive world

On SOME (meaning a FEW) motors you can drip some oil on the bearings.