I had a gentleman respond to an ad I placed about any Farmall implements for sale and he has several. One is a disc I'm not familiar with, but interested in. He said it is a pull type, single gang. Here is the interesting part. He said you set your angle, reverse to set gang to zero to turn, travel, or whatever, pull a rope and the gang automatically resets to cutting angle. Cut that row, reverse to set at zero again, travel, pull rope again to cut. I've seen a lot of old double & single gang discs around here, but none that had this feature, or none that I noticed. Could be common elsewhere. Sorry, no pics yet. Any help appreciated.