If it is truly a Ferguson plow, you are likely going to have difficulty. A friend gave me a "free" plow. The shares were pretty much gone. It had a 3 hole pattern on the share, with the hole closest to the point about an inch or so lower than the 2 trailing holes. I went to many different local dealers trying to find replacement shares, no one had a steel share to match it. I did find a place in Iowa that made them.....$130+ for each share - I'll pass at that price. I eventually found a local Amish family that stocked a ton of shares. She had what I needed, but only in cast iron. I took them home ($40 ea) and they bolted right on. I plan to use it when the weather cooperates, I don't know how the cast will hold up, but it was the only option I could find.
Post a pic if you can and I'll be able to see if it was like mine. I hope you have better luck than I did. Several posted to a similar question by me and suggested just getting a share and using a torch to make the necessary holes. That was going to be my next move until I found the cast iron shares.