See Don Moore's Simplicity 7013S: See his comments and link below.
I just recently purchased my Simplicity from my Father-in-law who traded some work for it. Right now I am using it to till my garden and to till up a section of my yard for a sidewalk. The mower is torn apart currently waiting for parts to come. I intend on restoring it when I get some other projects done.
Check out Don's Northwest Tractor Pullers Association (NWTA) homepage. Don, thanks for sharing with us and I apologize for the slowness in posting this.... Kent