Thanks everyone for the replies. It looks like I'll have to change my handle now!
At least now I know what I have. I really appreciate the help. I did see the 4240 set up manual on line. I'll need  to read it now so that I can set this plow up properly. I did notice the uneven ware to the center plow mould board. The others look ok. 
What does centering the draw bar do? Are there some basic guidelines to setting up the plow? 
Thanks again for your help.
Chris