Hello wce That's a pretty famous design. It reflects a time when domestic mower blades were still reflected in terms of cutting and catching.
This was a great blade holder, but note the theory here. The blade holder presents as aerodynamically neutral. The blades did everything else - throwing and catching.
Later, Victa would change their design philosophy about that.
The Green Book says it all ... Note AUS was still using SAE sizes after AUS metrication.
Hope this helps. ------------------------------- Jack
