Draggin8

Recently I drove the H653LT (SN1004) for the first time! Lots more work to do, but driving would let it 'tell me where it hurts' ...

One area of wonderment is the TriPlex transmission. It seems to operate well, but I wonder about the shift linkages. The top photo above shows the two shift levers - 3-speed on left, 5-speed on right. The lower photo is a close-up view.

Each of the shift levers passes through a captive steel plate with what appears to be a 'clamping' or 'locking' bolt. With that bolt loose, the steel plate can move vertically or side-to-side half-an-inch or so, with corresponding movement of the gearshift lever that passes through its center.

What is the purpose do these sliding plates? Where should they be positioned?