Snap coupler implements, drive sprocket needed

Saw an old computerless friend at an auction yesterday and he told me he acquired a unique find. From the original owners son he purchased an all original D14 with snap coupler implements that was bought new, always stored inside and included the original manuals. He said he got a plow, disc, planter and grain drill with it. I knew plows and disc's were pretty common, assumed planters were produced but would be scarce but had never heard of a grain drill. Ironically at that same auction another old friend who used to work at an Allis dealership was there. We visited about the drills and he said he maybe saw 2 of them while at the dealership so they must be rare. My friend asked that I do some online research on here to help with his needs. I guess there is a drive sprocket that mounts on the tractor to make the grain drill work and he doesn't have that so he's searching for one of those. He is also unsure if he'll want to keep the planter and grain drill and is looking for ballpark value information.