Newell Gurus

Hello.
 
I am hoping to locate a good resource (or resources) for Duo-Therm furnace parts.
I have 3 Duo-Therm propane furnaces in my coach – Model # 90020-813 
 
I know I can get circuit boards through Dinosaur electronics.
 
Does anyone know where I can locate a blower motor for these furnaces?
The blower motor is a Duo-Therm 3-18030
 
Are there any good resources for the sail switch and limit switch as well?
 
Thanks.