For the rusted rocker jacking point I ground away the rusted area and surrounding area of the heavy under body coating then using pop rivets with the heads in a recess made by drilling a shallow dimple using a reground 5/16" drill. This hides the rivet head in the patch material. I used a fairly heavy pice of galvinized metal. Then a light grind to feather the patch and spray with a black under body coating, two coats and the patch is gone. Don't use as a jack point any more. The rivits are on 3/4" spacing. Aluminum body rivets 1/8" stem with steel pull pins.
By this time you are good with tin and rivets and can repair the battery area rust the same way. The underbody material can be painted after it is real dry.
I use a shaker can product called European Texture Rubberized Gravlguard from NAPA. It looks exactly like the factory coating

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1984 300SD turbo 126
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