I don't know if anybody here is aware of this, but all the Farmall tractors that you've got listed, are built by International Harvester:


http://www.imcdb.org/vehicles_make-Farmall.html


http://en.wikipedia.org/wiki/Farmall_tractor

This is just a fact that I thought I'd let you know about, since you have it separate from I.H.C.