Bassin Guy - there are numbers on the hull where it had been registered before.
Look on your registration papers or title and see if it states a model number.
Measure how long your boat is:
Measure how wide your bottom is:
Jon Boats are modeled with those two numbers.
For example - if your boat is 14' long and 36" wide across the bottom,
your model number would be 1436
Gamefisher would be the manufacturer or make of the boat.
So, the proper name would be a Gamefisher 1436.
and your boat looks to be in very good condition. Unless you have a LOT of leaks,
I see no need to seal the entire bottom. Just focus on the leaks.
Put your boat on very strong saw horses (not plastic) or concrete blocks and fill it with water.
mark your leaks with a marker - drain the water - turn your boat over - address the leaks with 3M-5200 fast cure.