OK - so I went and I still don't have much insight on the truck.
When I got there the owner told me that another person is having the truck looked at, at a local shop. So we (both the truck owner and I) went to that shop, and found out the truck was on a lift. The seller asked the shop-owner if we could look at the truck and got a very stern and unnecessarily rude refusal.
All I could see standing outside the shop door was there was some surface rust on the rear axle and coil springs. The truck itself and most of the frame looked rust free, but again I was looking from at least 20ft away. The tires seemed low on tread too. The truck itself is absolutely bone stock and the owner claims to have never taken it offroad!
The owner claims to have bought it new in Odessa, TX and then kept it in Houston area until 3 years ago when he gave it to his nephew to drive while he was at college here in Madison WI. That means truck has seen at least three WI winters. The owner also said that the seat leather is rough, but I obviously couldn't have a look myself. The owner did not recall ever having a major service done (so no head gasket or heater hoses etc.).
I couldn't wait any longer for the repair shop to be done with their inspection so I left.