Potato plow or potato digger? Neither. When I grew up on a farm every family had 1/4 to 1/2 acre of potatoes and no one owned a specialty plow for potatoes. We used the same bedders used to throw up beds for row crops every year. I still use the 2 bottom bedder bought new in 1958 with the 801 in my signature. I suggest you do the same because one plow can be taken off and the other moved to center for digging then reconfigured for other uses until next potato crop. A single bottom like pictured in post 3 can't build rows on your tractor because wheels can't be spread far enough apart. You can mount 1 plow off-center on a bedder or tool bar,make a pass then make a second pass to complete bed. The key to plowing potatoes up without cutting them is setting point to right depth.
Chains help tremendously on ice and a little on firm ground but can't equal lug treads in loose soil or mud.