Hi Trev,
I think I measured mine from the GA on sheet 1 of the drawings. The front are 1.1/4 below the lower edge of the frames and the rear are 1.3/4 below the lower edge of the frames. Material is 1/8 thick and the joggle is 3/8. The front are hard against the cylinders and have 3 x 6 BA screws vertically, the rear are “T” shaped with 3 x 6 BA screws horizontally.
Hope this helps.
Colin