On the rivets, I'd thump / dolly them.
Grab a tube of automotive windshield sealer.
It's thin RTV /Silicone stuff and will flow tight to the edges of the rivets.
Glop it on, let sit just a minute, and wipe off to the center of the rivet head (of course on the outside).
I've had very good luck with it in the past.
I've had a couple of them 18 hp years ago. Thought they were very good motors at the time.
Keep / Flip?
I'd do some basics and run it. Keeping an eye out for something you really want.
Use this while modding a new one if you go that route.
Nice thing is, you can keep and use what you have (for years) and not loose a red cent from depreciation.
Remember too, the more you mod it the more you put into it,, and although it may become perfect for you,, it could be exactly what a perspective buyer does NOT want.
Like for me, I want open and light. Nothing for a fly line to hang on. I'm not a fan of decks on small boats. Playing in the ocean, I prefer a low center of gravity and light like a ping-pong ball. Wood is heavy, wood with wet carpet is even heavier.
And some bluefish, squid, and clam drippings on the carpet get fairly ripe in short order.
Then too, my pond (the Atlantic) may be different than yours. #-o :mrgreen:
Just my $0.02 :wink: