Thanks, Bill
I now have two versions of the 1956 TDB, but both are early versions (Nov. 1955 for 1956 Trucks) that did not list option numbers (for exterior colors). They both have beautiful paint chip pages (I'll scan and post them later today). Dupont codes are provided on the sheets for all exterior colors and combination. However, RPO codes are not shown on paint chip sheets.
For example:
Arabian Ivory (two-tone top color, I think): 93-58186
Empire Blue (bottom color, I think): 93-2528
On the individual model pages in the TDB, the Color Options preface-code are given:
Single (exterior color): RPO 234- (as you pointed out above)
Two-tone: DeLuxe Cab (exterior colors): RPO 443-
Two-tone: Custom Cab (exterior colors): RPO 444-
Perhaps the "Combination Number"
on these 1956 DuPont sheets are the suffix codes to the above RPO preface codes?
__________
Added later:
1956 Chevrolet Truck Data Book - Exterior Colors
