1966 Panel inner fender color
 

Here is one for the experts

I am working on a 1966 C10 Panel truck built in St.Louis, Vin Ending S102531, this is an early build truck.

The truck has only been painted one time and the engine compartment was blacked out. But the black is flaking off revealing medium fawn paint that looks original to this truck? I have never seen or read about anything like this?, See pics, any info would be appreciated.

Medium fawn paint on the inner fenders, heater blower housing, and radiator support.

Any information will be appreciated. BH