Boat / Trailer Registration

Hello all,

I recently begun restoring a 14' v-hull aluminum jon-boat that my family bought back in 2005. They originally only bought the boat for the motor that came with it, so i have no documentation on the boat, i only have the HIN off the transom and the New Jersey registration numbers that are still on each side of the bow from 2005(not even a registration card). The owner had gotten the boat titled but then lost the paperwork. I can still easily contact the old owner.

For the trailer, the only documentation i have for that is an expired registration card and the VIN stamped on the trailer.

I would like to register both in New Jersey, however i am almost positive i will need to produce more documentation. Has anyone gone through a similar process? i understand it varies state by state.