I have a '54 6100 that of course originally came with the 2 speed vacuum switch under the dash. By the time I got the truck that switch was removed and a vacuum switch added to the gear shift.The problem is the know is long gone so you only have a cable to push or pull which can be quite difficult. I was able to acquire an original 2 speed switch and it does have some linkage. But I can't tell if there is anything missing and how it actually all goes back together. Can anyone provide photos and/or a good diagram so that I can try to get this back to original?