Hi ronniedean1234. Yes I have posted on the MOC and tried the dealer where I bought the Montana. The parts department had very little interest in locating a discarded motor. They'd likely be very helpful if I wanted to order a new one. I believe Lippert's price was over $400.
I might take the motor in to a couple of RV dealers and try to talk to a repair tech. They'd be the ones that would know. The rear stabilizer by Lippert is probably installed on many brands of trailers. The motor corrosion problem is fairly common.
Glad you were able to help out your relative.