Trying to find some Yetter 2968 dual-wheel fertilizer openers for a JD 1770 NT. Would like 8 of them, preferably new but would consider used. Looking to take off my JD single disc openers and put the Yetters on instead. Seems like everywhere I've called or looked they are sold out for who knows how long. Does anyone have a lead on where I could find some? Thanks.