ABG 200 differences

[Problems]

I'm just about done restoring my 1940 john deere model A and I'm getting started on restoring one of my cultivator sets for it. I'm noticing a difference in the 2 sets I have though, I guess different years used slightly different parts. Does anyone know if any of the differences pictured are better or more rare than others.
The first picture is a set that came with my grandfather's 1941 model A. And the second picture is the set that came with the 1940 model A.

What I mainly notice is the change in the shield hooks(one is 2 bolts and one has one bolt), and the arm lift assemblies on the upper most bar right in front in the pictures.

 

[Problems]

One other thing is the differences in the front frame, again 1st picture is 1941, second is 1940.

One uses a clamp at the base, while the other is cast at the base

 

[Loosehandle]

I'd go with the first one, seems in much better condition. I always thought those quick tach frames were later, maybe someone will know.

 

[Leroy]

Neighter one are orignal to either tractor. The quick tatch did not come about until after the war think with the pressed frame tractors. It could be added to the older ones. And that ABG 200 is later model