Panel prices are crazy, man.. unless the body is absolutely shot (and rust dosen't mean shot) you could easilly sell it and buy a truck.. and maybe even make some money in the process!
I'd guess a NAPCO Panel is probably even MORE rare (that means more bucks) might have enough left over after the sale to side your house and put your dog thru obedience school.
For switcharoo conversions, i've seen at least two Task Force year trucks parked on mid 70's Chevrolet 4x4 frames (and old rusty 70's Chevy 4x4's tend to be cheap, plentiful, and lots of avaliable parts)
Not sure how a 70's 4x4 rates against a old NAPCO, and maybe you're wanting to have your finished product be "period correct".
Either way you go, there are plenty of folks on here who can help you out.
