Thanks Tom !
I am probably wrong but at first sight my two holes from each side (on both sides) are not at 90 degrees, as on the drawing. I must see it more carefully
I think to make one adjustable system to correct all the relations between the gear change lever and the opposite end at the gearbox. The major and principal forces are applyed along the length of the big bar, not sideways. So it is not difficult to make such a system.
Let’s keep in touch, and sorry for my broken English.
Joćo