Lance:

There were at least two types of disc plows available for the CA:  The first type is the semi-mounted 2-disc  that was manufactured by Athens Plow Co.. This is essentially the same 2-disc plow that was used on the B and C, but the mounting brackets are different and allow use of the traction booster system.  My parts manual only shows this plow as being available with the pin hitch.   Standard disc sizes could be either 24" or 26". 

  There was also a fully mounted (pick-up type) 2-disc plow that was also made by Athens.  These were made in both Snap Coupler and pin hitch styles. Standard disc size was 26".  New discs for either of these plows were available through Agri-Supply as special order items the last time I checked, although you would need to specify the diameter, thickness, concavity, bolt size, and pattern. 

My 2-disc semi-mounted plow for my C has become a favorite plow to take to plow days when I don't know what kind of ground we will be plowing.  It rolls right over our plentiful Shenandoah Valley lime stone ledges, cuts 2" and 3" roots, and is very difficult to plug with stalks or other trash.  The worst part is getting it on and off of the trailer...  The best part is all the people with wide eyes saying "What's that big funny looking thing you're pulling with that little bitty tractor?"

Charlie:

I'm afraid my C ain't the most photogenic thing around.  I call it my mongrel pup, since it is painted with red and gray primer, as well as some orange here and there, with plenty of rust sprinkled in for good measure.  Now that everything, and I mean EVERYTHING on it has been rebuilt, I guess I really should paint it.  My trouble is that I did that once before, and it just ruined the tractor for me. I do wish I had some video of it cutting those big tree roots this spring.  We were plowing some ground that had been in no-till for a looong time, and the trees were about to take over.  Everyone who had spring trip moldboard plows spent a lot of time backing up, either to reset tripped bottoms or to unplug their plows, err... rakes.

After my last post, I thought to check the club's web page in case there might be pictures posted.  Guess what!  Not one, but three pictures of the mongrel pup with the Athens 2-disc plow.  If you look carefully at the exhaust, you can tell that it was working pretty hard.  I am just about convinced that you could plow an asphalt road with one of these plows, provided that you have enough power and traction.

Edit:  Pictures have been resized.  I apologize to Lance, as it appears that I may have hijacked his thread...  

BillP:  I haven't tried the plow trip spring yet.  As you can see in the pictures, I went ahead and used the plow without the spring.  These pictures were taken at the Shenandoah Valley Steam and Gas Engine Association's plow day on April 10th of this year.  In two of the pictures you can see that the photographer caught me playing "manual traction booster" with the hydraulic lift. I eventually found a depth setting that eliminated this problem.