Not entirely sure. I'm guessing somewhere in the 60's. My great grandfather bought it years ago for the farm. The story goes it fell off a rail car and he bought it fixed it.
That’s pretty cool story! Glad he saved it! You can look up the serial number on it. It will tell you. He could have changed the engine in it if it got F..ked up from a later model. It’s got me curious now lol.