Late A Body rotor measurements

I'm hoping somebody might have a disc rotor on a shelf somewhere -

I need the measurement at "B" for a 73-75 A Body disc rotor...NOT including the hub.

Basically I just need the rotor and "hat" height measurement only to compare to our Aussie Valiants.

(I'd like to be able to use the US slotted aftermarket rotors while retaining our hubs - if possible)