And believe it or not I found another one today with the big rubber disc, seems they might have been fitted to the high arch mowers maybe to create a bit more lift for the clippings?
Ahhh yes, that is the one Victa put on their later build Vortex models as a replacement for the large blade disc with stubby blades developed by the CSIRO. Victa had to pay a royalty to the CSIRO for the use of that blade carrier design, so must have developed that add on to their existing carrier design to get around it. Whether it was as effective is up for debate.
I was given a spare one when I got a Mustang GTS on EBay a few years ago.
