Welcome!
YOU NEED TO SANDBLAST THE FRAME!
At that point, the welds need to be looked over, and if any appear to be compromised, have a welder grind them out and re-weld them. Any pin-holes can also be welded up.
Next, don't paint the frame, HAVE IT POWDERCOATED.
The frame SHOULD be able to be salvaged...but the old girl has been exposed to Pensacola coastal salt air, so it's gonna take some work.
~Joe