Electrical problems are so time consuming that rather than waste money on labor shops that specialize in electrical problems yank out the entire factory wiring wire brush off loose rust and fix any rusty areas with a sealer before installing a complete wiring harness that they made in their shop or bought from American Auto Wiring.
Like I said steel is a lousy conductor. In the plastic Corvette there is twice the wiring as found in a production car, because every circuit has it's own grounded return wire. There are no electrical circuit corrosion issues on a first through fifth generation Corvette, but it comes with the added price of doubling the number of wires.
There are shops that specialize in just automotive electrical problems, but they are pricey. You can find them on line (or in an old yellow pages phone book if you have one still). Replacing everything is labor intensive but after buying a AAW wire harness set (there are three different harnesses in a low dollar car, more if fully optioned with power everything) it is straight forward R&R (remove and replace for those that don't understand mechanic talk). You can do it yourself for less following the instructions.
I used Painless wiring in most of my race cars or built my own wires as DC circuits are very simple (compared to a Delta or "Y" 440 volt three phase AC wiring circuit in a commercial building). It really boils down to removing and replacing a wire bundle. This is infinitely easier than taking the bundles apart and replacing them one wire at a time.