Denny,
Just wondering what your aversion is to taking it down to bare metal? Although it was a pretty good finish in its day, that old Dulux baking synthetic enamel doesn't hold a candle to the newer epoxy's, 2K's, and urethanes applied over a properly prepared surface. I'd hate to go through the work and expense of a good repaint and have some of the old underlying coat fail. Plus you WILL need some bodywork. Trust me, no matter how straight the truck appears now, once you start priming and guidecoating, the amount of lows and highs will amaze you.
It really won't be much more work to go to metal if you have to remove some of what's already on there. In fact, my truck had one of those 29.95 Earl Scheib specials applied about 30 years ago over the original paint. That old Scheib enamel was alot tougher to remove than the factory paint. Once I got past it, the factory stuff sanded off fairly easy.

Bob