I believe this to be a cast iron and original Crank Guard for a 4HP Fairbanks Morse H engine! Please do some measuring and comparing on your engine before purchasing to save us both the time and headache!!! The mounting hole spacing looks to be 8 on centers. As you can see in the pictures the mounting holes have a “chunk” missing from each side. I think with some time this could be fixed up or just put larger washers on when installing. Please see all pictures for the absolute best description.