What Joe shows above in #10 looks just like the factory invoice to the dealer. This is what Lois Emminger had and is still available for some 55's, most 56 and 57's. I never heard that she had the "build or ROT sheets". I guess if the car went to be tested and not sold it was billed to engineering which would make sense since the car then went out of the system just as it would if it had been sold. And engineering would have the cost for internal cost control.
I say most because some are missing. When I inquired about mine, it was missing.
Note that gas was 41.4 cents a gallon.
Midland Park, NJ
56 TBird, 54 Ford, 48 Ford, 64 Fairlane