I found this partial catalog in a used book store and once I did a bit of googling, I was introduced to another little-known inventor/ manufacturer of the late 19th Century.
D.C. Stover started manufacturing windmills in the 1870s but his inventive mind came up with various machines including feed grinders, spring-making machines even barb wire. One comprehensive and successful line were stationary gas engines, shown here in this 1920 catalog.
Apparently the company closed down in 1942, though serial numbers and shipping records still exist.
A short history of Stover here.