Uggggg.. Mobile home open rims and tires..
OK, from "been there, done that" point in my life.
Bought a early 1980s 26ft TT that also had set 12yrs in a campground. Camper was 25 miles from my home.. The tires on my trailer had lots of air checking and cracks but they held up long enough to get home.
Also had to deal with getting a mobilehome off the land I was purchasing, the bank didn't like a mobile home on the land.. Had to have a mobilhome mover come in and pull it to some land that was owned by my DWs family 15 miles away.. That mobilehome had been sitting on the property well over 20yrs.. The Mover aired up the tires and away they went with it..
Air the tire up, set to sidewall pressure all around and see if they hold air.
If tires hold pressure, proceed to tow carefully at speeds under the speed limit since you are towing a pretty short distance. Might wish to ask your towing friend if they have any spare mobile home tires and rims handy just in case..