HARRY - Yep, just worked the tire desk for Farmall, and from time-to-time the IH rep up in Fargo at Stieger would call me to get some special tires that Stieger couldn't get. One time he called and I got him some tires. About two days later he calls back and leaves a message that the tires came in and thanked me. An hour later the Purchasing Mgr @ Stieger called and acted like he was mad, "How the HECK did you get those tires? They're on allocation!" I told him I just called Good-Year, or Firestone and ordered them. I suggested if he needed some more he should talk to our rep up there and I could get him some more.
I did meet my counterpart @ East Moline once, but never from any of the other plants. The girl that did my job in Waterloo at that "Other company" sat behind me in Spanish class my Jr & Sr years in high school. I talked to her several times after I found that out, She was a former cheer-leader.
Far as how many wheel/rim suppliers IH had, for ag & construction equipment there were four. Electric Wheel in Quincy, IL, which became a division of Firestone in 1957. Then there was French & Hecht in Davenport, & Walcott, Ia. They were a division of Kelsey-Hayes which was a division of Fruehauf. And then there was Motor Wheel up in Mendota, IL, which was a division of Good-Year. And last was Titan Proform up in Toronto. They actually worked with French & Hecht in producing steel center disc wheels. Titan had the press capabilities to produce the centers and F&H had the rim rolling lines.
I suspect there were only two suppliers to LVL, EWC & F&H, they were the only co's that specialized in the small wheels. Motor Wheel possibly made some too, seems like I saw a "GY" stamp on one of my CC wheels, but most I've seen are EWC. I know an off-brand L&G tractor used a cobbled up flat center disk wheel made by some welding shop because they didn't plan ahead when either EWC or F&H went out on strike. They're pretty rare now since the center disks were too thin and they all cracked around the bolt circle. EWC went on strike for several weeks in either late 1980 or early 1981 and I wouldn't say I had no problems, but I kept 145-150 tractors a day shipping with EVERY wheel, rim, & tire they were supposed to have. I was on a first name basis with the Gen'l Manager of F&H daily but I got my parts.
Here's a little time line about who was and who they are now in the wheel/rim business. As you'll see, all roads led to TITAN. I actually met Maury Taylor once when he was down visiting F&H. Even went out on the Mississppi River on his yacht one night with the people from F&H and my counter-part from IH EM.
http://www.titan-intl.com/about-titan