gearbox selector options

Hi all,
While being busy to find good suitable gearbox command for my mk3 project i stumbled on this option on a french website... which i think could be totaly put over to a Porsche G50 box command. this is little single seater formula car with reversed Renault1968 ( engine and gear box)
You have to adjust measurments to Porsche G50 box, and in this case the spring used in this sample is valve spring from old briggs&stratton lawn mower.