The only code I can think of is on the clock which is 1812, you have to find the key which looks like a small bent piece of metal put it in the clock and keep turning till you reach 12 minutes pass 6  (18.12 in the 24 hour clock)and a little compartment will open there you will see a key, click on it, it will go in your items inventory, go back to the national reserve and that will open the safe where you find the blue print hope that helps.

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