Brickman,
The first number I can't help with...it could be rear or tran serial number.
The middle number is the Chassis Seriel Number;
1WA06-6316
1 = Flint Assembly Plant
WA = 1940 1-1/2 ton, 133" Wheel Base with single or dual rear wheels
06 = Month built (June)
6316 = Unit number starting at 1001
The third number is the engine serial number (also found stamped on the passenger side of the motor on the flat machined surface near the distributer);
T-3585476
T = Left Hand Drive Truck from Flint Plant.
3585476 is the unit number.
Note, The first engine from Flint in 1940 was 2697268...I don't have the last number in my records. They also made engines at the Tonawanda Plant and their numbers went from 105462 to 221935.
Hope this helps...
Mike B
