This is the first model plough and was designed to be attached to the very first Fordson Major tractor. It also works quite nicely on the Massey ferguson as shown here but the top link would have to be detached to let it down for operation and it would then look a bit odd!
These early ploughs are quite sought after now, being replaced after a few years with a simple blue one with shiny, chrome-plated shares with no top linkage.
This one is more or less as new.