Ferguson used top quality materials and field tested his implements exhaustively. If you can find a Ferguson implement in good condition after all these years, grab it.
The Field Cultivator referenced by Ken Sweet in Post #9 is a copy of the original Ferguson implement, which Ferguson called a "tiller" and Ford/Dearborn called a "Field Cultivator". Designed and first built by Ferguson about 1934.
Ferguson CULTIVATORS are a bit different; see photo.
Ken Sweet occasionally offers original, old, Ferguson Cultivators.