1964 was the first year the Wilmington plant built full size Chevys. There are a few unique things about Wilmington cars. The rear body braces are the most dramatic difference from other plants. Since the BOP cars built there used them, I'd venture that Fisher Body standardized their body jigs for the rear trunk area which saved them floor space and money. It also allowed them to have one assembly procedure for all the rear floor pans. Notice that the braces are independant of the quarter panels. They tie the rear of the floor pan to the wheelhouse. It turned out to be a good idea. A common problem with these cars was that after age and the settleing of the rear body mount (just behind the axle), a crack would develop on the top of the quarter panel from the C pillar to the belt line. It's very unusual to see that crack on a Wilmington car.
Wilmington was also one of the few plants that used such a detailed build sheet (and usually left more than one in each car). Another "oddity" of that plant was that the trunk lids did not get an insulation pad between the panels. Also, their method of coding for accessory codes (also like Southgate) was to only code for certain major options, like A/C, tinted glass, vinyl roof, etc. And when they did, they used the actual RPO codes rather than something cryptic. They (like Southgate again) were also the only plants to use 3 letters to designate the colors, upper body, lower body and wheel color. In your case, FFA= silver blue, silver blue, black.
Dave, I'll be in touch later with some other things I noticed on your car. Post some more pictures of it once it gets a bath and some polish
Verne
