That is interesting Paul, so Victa went back to the old faithful oval blade holder instead of the round one they used on the earlier ones. They used a round disc on many of the earlier 18 inch mowers so they are not too hard to come by, just make sure the center hole and blade mounting holes have not been flogged out .Blades are from the 600 slasher and are 140mm center to end, this is how they get the wider cut