I spoke to the Benson Ford Research Center, and they may be the best source of help.
They recommended that you send an email to them requesting a letter that would confirm that your ID number is consistent with a 1939 Ford. I explained that you would not be asking them to confirm anything other than that the number was a 1939 number ... nothing else.
The Benson Ford Research Center in Dearborn, MI, sounds pretty official and may do the trick.
I personally would send a suggested reply that cleverly included the word "black" ... such as, "Our records indicate that your black 1939 Ford V8 with identification number, xxxxxxxxxx, was produced by Ford approximately during the month of xxxx, 1939." Or something that did not directly specify is was black originally.
The lady I spoke with was very helpful and careful to explain that there is a limit what they could do. I assured her we were trying to preserve an old Ford.
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