No one is going to touch it. No way to adequate document pre and post tow damage plus trying to determine if the fire has compromised the body.
The OP's intentions are admirable but the idea of using 20+ year old RV's a shelter for homeless vets is not the best use of financial resources to help someone in need. Besides the acquisition cost and then the transportation cost the cost to make them livable will be equal to what already been spent. A small, functional, towable trailer would be a much better use of resources.
As an example for $4500.You're not going to find a class A or C for under $1000 that is both driveable and livable. Most will have substantial water damage, rot and a chassis that has not seen even minimal preventative maintenance in a very long time. Either change your business model of buy a lowboy hauler. It will pay for itself after the fourth barn find RV.
2006 Hurricane 31D built on a 2006 Ford F53