What was the difference between the IH9 and the MCD9?I see a lot of old mowers around here and they all have IH#9 on the tool box lids. Seems like some of them are built wider and some seem to have heavier gear case covers.

McCormick Deering was bought out by International. The number 9 came in 3 types. Regular, High Gear and Trail Gear. With the trail gear being the heavier made. The trail gear was made to be pulled with a tractor or truck. Some of these were made so that a second mower could be pulled behind the first, turning a 5 ft cut into a 10 ft cut. The number 9 is often referred to as the McD9 or the international 9 depending on who you talk to.

McCormick Deering wasn't bought out by International.

The two largest reaper manufactures McCormick harvesting machine company and Deering Harvester company merged with three other smaller companies to form the International Harvester Companies. They continued for many years to label their products from the original brand/line. Since both McCormick and Deering both made mowers before the merger, after the merger, mowers were branded McCormick-Deering, But all products had the International Harvester Company logo An IH superimposed over a C. in 1920 P&O plow company was bought and plows for many years were sold still a P&O's, again with a IHC logo. Certain lines of tractors were called McCormick Deering, rowcrop versions Farmalls. Only in IHC's later years did they really start branding things as "International" which is why most refer to it as such today.

Sort of like saying, I bought a GM car, well did you buy a Buick, Cadilac, Chevy, Saturn, Hummer, or pontiac?