[Double Venom]

"Jet-Coat", is but one of many coaters. Find one that does both inside and out.
Heat Tape is the absolute worst thing that you could have done! I suggest being very careful taking it off. Only thing that makes sense, that they haven't burnt out, is because it is a Cobra and wasn't driven for long periods of time.

If they are solid you will be amazed by what sandblasting and powder coating will do!
Who ever you use make sure it is HIGH HEAT POWDER COATING!
DV