Yes Gadge, Id have to agree with the forward planning, as Victa was often ahead in designing its future models at or before the release of prior models. The 9C carrier was NOT ever meant to carry 4 blades at once. The 2 level holes for Rotomo,Special etc...and the raised blade points for the catcher models. So one plate fits all. Thankyou for your thoughts.
And yes of course 4 blades are better than 2 at a level height. I also use four blades on my own mower and it makes a huge difference.
I'm aware of the 9C carriers function, Im far more interested in the questions from the prevoius post and also the following. Im looking for accuracy of fitment.

The Model 1 Rotomo used a different blade plate than that of the patent variant. At this point its my opinion that they possibly sourced this plate externally and modelled the Patent Carrier from this.
They are similar in design, with a few additions made to the Patent version.
This is why Im' asking when the patent was approved for production, to ascertain when the Patent version was fitted, and to which model.
From the the release of the Model 1 to the Sheerline I have found 4 plate variations
Model 1 (sample image coming)
Patent carrier with Humps...9A?
Patent carrier with no humps 9B
The Multi point 9C
The 3 Patent style humped carriers I have are on early to mid model 2 Rotomos.
All the rest are 2B carriers.
I remember you (Gadge) saying you used to change all the 9B carriers for the 9C for ease of fitment. What confuses me is...Ive never had a Special with a 9B plate. Does this mean they changed every one? I cant see it.
My point is, in your opinion what year was The 9C carrier released and is there any documentation?
Cheers.