Okay.  Here's a question for you U-Frame knowledgeable folks.  What were the primary changes from the 12-20 to the Pacemaker?

My 1936 Pacemaker was the 129th one built per it's serial number (107129).  A couple of people have commented that it has some 12-20 features, perhaps carried-over inventory?  In particular, the drawbar set-up, which has wider drawbar with less thickness than what I generally see on Pacemaker's.  (Which, by the way, on my tractor is broken-off just behind the support - a good indication that it needed to be thicker metal!)

Here is a photo of my Pacemaker in its mostly original glory.  Comparing it to the 12-20 above, I can see that the radiator top casting is different, both in the size of the riveted-on Massey-Harris name plate, and in the radiator cap.

What are other key differences between the 12-20 and unstyled Pacemaker?

Thanks,

    JB