1921 saw the first 15-30's roll off the line. they started at serial number TG112
W-12's started with WS503 in 1934
O-12's started with OS512 in 1934
I-12's started with IS512 in 1934
so not all of them started with 501. in 1938 when all the 12 series tractors turned into 14 series tractors instead of starting over like one would normally think to do with a new model, they simply kept going on the numbers where the 12 series left off
Byt hte sounds of it the parts book states the First WD-40 was 508. but theres a guy out there who claims he knows of 501 2 3 and 4? (i think he owns one) what do you know about them?
ewwww, after 39 you guys all have me stumped but im pretty sure your corect on everything starting at 501
one other one i forgot was the International 15-30 (Flaming four) they started at TS101 in 1915, revised in 1917 and had TW-101 then, and in 1918 changed once again and started with EC-501
When you get into the newer ones 1206 started at 7501 and the 1456 at 10001, 1466 at 7101 and the 86,s at 8601
the SW6TA started at 10001 too. but im assuming since the SW6 got over 9000 they just rounded off to start off 1954