Most of what you show there is pretty familiar. I guess you will have to sand or wire-brush to get down to either sound paint, or bare metal. Don't forget to etch the metal. FastJeff has a technique for deck fittings: He drills out the bad holes and installs rivnuts, then uses a machine screw to replace the fitting. This has worked well for me. I installed a folding ladder onto the swim platform, and chocks for the (heavy) dingy, using rivnuts and they worked fine. You can get them at
http://www.mcmaster.com/#rivet-nuts/=dzsbhg
The best thing about rivet nuts is that all the work is "on top", no one has to go underneath to hold a nut. I install them with a large rivet gun, but you can use a machine screw and a couple of nuts. I put sealer on them before putting them in, and then wipe off the excess. No leaks. If you get stainless flathead socket capscrews for the fittings, it looks awesome.
1975 32' Flybridge Sedan, twin Perkins 6-354 diesels, 1:1.53 velvetdrives, 16 X 19 props. Merritt Island, Florida