Not too quick!
'Farmall' started as a model name, but evolved into a brand name.
http://en.wikipedia.org/wiki/Farmall
The IHC names are always troublesome. We have the corporation, a number of companies, many brand names, and lots of models, sometimes similar or almost similar models sold under a different company and/or brand name.
To what I know they should either be listed with 'Farmall' as the brand name, or, depending on the year, 'McCormick-Deering' / 'McCormick' / 'McCormick International' as the brand name and 'Farmall' as part of the model name.
IHC was always the company, not the brand.
I will try to find better information, but this seems not to be so easy.