Re: Aluminum vhull to bass boat
Many of the bench style seats are structural components that help the boat keep it's shape. Heavier aluminum hulls may depend on the benches less for structural support. They are also likely filled w/ styrofoam flotation, removing them & adding additional weight and not replacing the flotation foam elsewhere isn't wise.
Any bracing that is thru the green portions of the inner hull are below the water line. Remove them & you'll have to fill the hole, stainless nuts & bolts will work, but a closed end blind rivet would work better, and you'll need to seal the rivet/bolt to the hull. Those above the water line still need to be filled & sealed but aren't as prone to leaking.
You might consider using a converted cooler as a livewell & adding clamp on seats. If the off the shelf seat brackets won't fit your bench tops very well, it can be accomplished another way.
You'd be gaining seats, not adding significant weight, not removing flotation foam, not be making major changes to the original structure & it's strength, and hopefully be keeping a nice inherited vintage tin boat intact.
Where in Ohio?