If you got insurance for it and they think it's a pickup then don't expect a "free" tow to be free when they find out how big it really is.
Another way might be to ask your insurance company about adding a vehicle IF you buy one. In my case I was going to look at and probably buy a truck, but didn't want to get insurance ahead of time if I wasn't going to buy it. They said no problem, you'll be covered under your other policy and you have a week (or two?) to let us know you bought the vehicle, just let us know when you get home with it.
You should be OK to drive it home on antique tags or a trip permit.... but how long is a trip permit good for?
In VA last I got one it was only good for a couple days. and last time I needed one was on a drive with a 61 ford truck from CA to VA, The trip was about a week, and longer than the permit would have been good for. I could buy and print the permit online for about $5, so I figured I'd drive till I got asked about it, and if not having one was a problem then with the lap top I'd buy one on the spot... I thought that might be a tad better than finishing the trip on an expired one. In the end no one asked and I never bought one, so that worked out well. May have helped that the truck still had CA plates on it... previous owner forgot to take them off.
If you chose antique tags you can either legitimately skip scales, or try to and probably get away with it. That same 61 ford this time with antique tags I later drove from VA to CO to WA to PA to NY and back home to VA, all in 14 days and half of it towing a 54 GMC COE, not once did I cross a scale or get pulled over. I did skip South Dakota on the advice of several truckers though.
Grigg
