Well, after three years of cutting, grinding, cursing and crying I finally got paint on
MY CAB I'm a novice at this... never painted a car in my life so take these tips with a grain of salt. Just sharing in case anyone is interested.
When you are doing your priming mask over the body color flange by about 1/8 to 1/4 inch. This way when you pull all the tape off to re-tape for the finish color you can feather out the edge of the primer smooth on the flange instead of having a heavy buildup of paint at the line between the interior and exterior color.
For the life of me I just could not mask those big openings with masking paper so I used
WHITE CORRUGATED PLASTIC that I bought at my local sign shop. I used it during all of the priming and sanding and then pulled all the making and re-taped it for the color coat. Being plastic the tape pulled off clean and I was able to wash each piece. Ignore the hood, I lost patience for my helper.
If you do this be sure you clean all the sanding dust from the inside of the corrugations otherwise it will blow out when you do your color coat.
Anyway, I'm totally relieved that this stage is behind me and can finally start putting this thing back together.