Chris - I've just looked in the Facnor Installation Manual and on page 26 it says: "Thereare two kinds of assembly for the lower fitting of the drum".
It goes on to show both the two plate option like mine and the split yoke like yours. It doesn't suggest one option better or worse than the other, although the diagram of the turnbuckle option (yours) DOES show an adjustable bottle screw on the bottom of the forestay, which would seem to make sense for tensioning.
Have you got a manual, if not I could photo the page for you, or contact them directly?
Stephen Godber
235/51 "Exodus"
Stephen Godber
235/51 "Exodus"