Your '83 Classic has an absolutely flat bottom, shapped like a pressing iron for clothes.
The rails are nice, but wear out over time.
Want a long term solution?
Turn it over, pull the rails, seal the screw holes, and re-glass over the hull. Then get a big sheet of aluminum, say 1/8 of an inch thick, and cover the entire bottom of the hull with it, sinking the screws into the hull with plenty of 3M 5200 and using screws with a type of head that won't be rendered irreplaceable by a little rock abrasion.
Make the plate a little larger than the hull's outline, then slit it every 3-5 inches at the overhang with a saw, and bend it up over the chines of the hull, using a rubber mallet.
I haven't figured out the cost of this, but it should give you a bulletproof bottom, so to speak.
I think you'd have to make the holes in the aluminum a little larger than the screws to allow the aluminum to expand and contract somewhat differently than the plywood and glass hull bottom.
Now you have a riverboat too, at least somewhat.
Got any good cheap scrap metal dealers in your area? (Access to good, cheap, metal and industrial surplus stores is one of the things I miss after having moved away from the Bay Area to Redding.)
Joe. :teeth :thup