[MikeP]

There are two types of gear change linkage to connect from the lever back to the gearbox input shaft - cable using the same type of cables used on boat outboard motors or a rod type usually using lengths of stainless steel tube running in spherical bearings with universal joints at appropriate points. The original GT40s had rod type gearchange linkages. The actual gearlever mechanism can be exactly as per original or you can make one up. general consensus is that the rod type gives the best results. I am changing mine from cable to one one of Frank Catt's Wealden Engineering rod types which give the best gearchange I have tried - very slick - like a rifle bolt. Do search and you will find lots of info and pics.
Cheers
Mike