I agree with Drew and Terry on the smaller tractor being the 20 and not 22.  I saved it over to my hard drive and enlarged it like Terry said he did.  Doing that you can see the 20/81 style grill that way, and also the side panels.  (I'm just not as familiar with the smaller tractors to have picked-up on that without blowing up the photo.)   Oh, well, 2 out of 3 ain't bad.  :-)

   JB