One persons White Elephant is another persons dream RV. Financing through an RV lending agreement is a problem, so it depends on how much needs to be financed and what other equity can be used. A line of credit as an example.
Helping a friend is noble, and I salute you.
What will the "while elephant be worth to the dealer in the future? I just traded in my 11 year old rig with 50k miles on it for a new coach. NADA was 60K, the dealer gave me 40K sight unseen. My lovely, well kept, well cared for RV was just inventory to them. I enjoy my new RV and I was content with the bottom line of the purchase.
Happy Trails.