I am most likely not correctly understanding this question, but here is a link to a page with
a 3-speed and a 4-speed steering-column floor seal. truckernix: Does your steering column have the two holes near the top for mounting a 3-speed shifter-arm "collar"?
I had a 1/2 ton '54 factory 4-speed but I do not remember if there was a hole in the floor for the 3-speed linkage rod. I will ask the present owner to check it out and will post his reply (if he replies).
Tim