The DA prefix on the contract number is Department of the Army. Most vehicles procured
for the military were on contracts from TACOM (Tank and Automotive Command) in Warren MI.
Colors and other special purpose items were specified by the services as required.
GSA also issues contracts for other government agencies and some DOD agencies.
Fred

1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine