USAAF contract numbers - can anyone date this contract?

[MiTasol]

I am trying to date a Curtiss drop tank part number 75-45-433-50 contract W535 AC15802.

Somewhere there must be a list of contract numbers and the date that each contract was issued, and even copies including changes (revisions).

If anyone can provide me a link to such data it would be most appreciated.

TIA

 

[Snautzer01]

contract W535 AC15802 - Google Search

 

[MiTasol]

Many thanks. Not the response I wanted as I had hoped the fuel drop tanks were a separate contract but still a very interesting document.