It could always be sold in N.H. We don't require titles for vehicles over 15 years old. In fact, our vehicles end up useless to many out of staters, because the state won't issue a title for older vehicles. I've tried going through them when I wanted to sell a vehicle to someone in Mass., and kept getting the run around, and I ended up not being able to sell it out of state.
My friend has the opposite problem, and bought a trailer from VT, where there was no title needed for it, and it had only been used on a farm anyway. But a trailer over 3k lbs. GVW is one thing we DO require a title for, and he's been fighting for nearly a year now trying to register it. Thanks to another member on here, I found out he can register it in Maine, so thats what he's going to end up doing.
Some states have ways to register them IF it came from a state like NH that doesn't require a title. It usually requires some extra paperwork, a copy of the old registration, etc.
Jim