Matt's measurement provided me ball park, at 30.2 mm. I think it is likely spec'd at 30 +/-.
I saw the drawing you provided (have seen that before as well). Interesting that those dimensions are not 100% accurate to the factory. That states the stock 1g rod small end is 1.140" (28.96 mm), but factory spec is 28.5 mm which is 1.122". I have not looked at all the others in detail yet.