Peter,
" s/m v-4513 2020" is the contract number.
If you search the forum, you will find some interesting info in this thread, where Hanno links to other threads on the forum:
http://www.mapleleafup.net/forums/sh...d.php?p=271837
David Hayward has this in his files:
S/M 2020 EC011QF assembled under Contract [294/]V/4513
If you than cross reference SM2020 to the Chilwill list, you will find the Census numbers for the Chevrolets and Fords in this contract. For your Ford the original numbers on the door would be in this range:
Ford H 4541694-4542693, Tractor 4x4 Field Artillery, SM2020