I have received 2 old Smiths speedometers, bought as 'parts' off ebay. I plan to use one for the speedo, and one for the tacho.
I stripped one down and fitted the BMW Z3 workings inside. I then cut the Z3 gauge surround, and mounted it around the face of the Smiths gauge. It came with 2 analogue odometers; trip distance and total mileage. These had to be removed in order to fit the Z3 stepper motor in flush, so I cut them down, removed the number wheels, trimmed them and fixed them in place.
This is the speedo, now ready to fit.