Hi,
I have bought two IH vehicles out of state. The first was my 62 travelette. Originally it was brought to san diego and put on ebay. I saw the truck and told him I was not willing to pay what it had already been bid up to at that point. The auction ended, the winning bidder saw it and backed out. Then he, the owner, took the truck back home to alaska. I contacted him, we eventually agreed on a price, I sent him 2/3rds payment and waited for the truck. Two months later he was knocking on my front door with my truck, and the current California registration I had insisted on as part of the deal.
So it can be done, but I wrote up a contract he signed before I sent him any money to help guarantee its safe delivery. I covered such things as what if he didn't deliver the truck, or it gets damaged while in his possession, or I don't have the remainder of his money when he delivers it, etc. But everybody was honest and it all went as smoothly as possible. If you want, I can send you a copy of that contract if you think it will help in your inter-state transaction.
However, I've recently bought another truck, a rust-free 65 c1500 4x4. It's in nebraska, and I'm here in los angeles. I have yet to figure out how to get it here, or where I'll put it once I do. It has a running, 85k miles 304 and 4 speed. I intend to part the truck out, taking the axles, doors and mirrors. Hopefully someone else will take everything that remains, including the d44 and IH axles from my c120 4x4 truck, but I digress.
Just want to say buying a vehicle in another state can be done, but be sure you and the seller have a good understanding of all the facets of the transaction first, and agree on all the possible "what if's" that might possibly happen.
Steve