Hi Tom,
Looking at the pictures closer, that is the carburetor cover that fit many years of the 7.5HP. It was also used on some of the 5, 5.5, 6, and 7 HP models, but those HPs were also sold with a smaller version of that cover. Here is a picture of a 7.5HP with the same cover your friend has, but with the proper Elgin green paint job. There is only one slight variation,this one has a hole for the fuel petcock on the port side.
JP
