Oh, I forgot to mention that the w55 gear bow would have to have the 18" extension housing rather than the 20" or the 25". If you got the other ones you'd have to do a bit of cutting to get the gearstick through the floor.
If you use the 18" one you may well have to modify the gearstick so it doesn't hit the centre console depending on what car it is going into. If it is an RA28 then this will need to be done, and no the gearstick from the w50 can not be changed into the w55/57/58.
The speedo drives are also different so your speedo will read wrong.