Just swapped the KMH face for a MPH one and was not looking forward to the job but it all went nice and smoothly, even setting the needle with a GPS speedo app.
While it was stripped I added a little dash pimp by colouring the surround with a bit silver aerosol and quite happy with the results.
Was gonna do it with a bit carbon vinyl but might do that at a later time.
honestly, very easy, to remove and to paint. I didn't even rub it down or use any primer as it is not exposed to anything. Just remember lots of light coats rather then all on at once, if you use light coats it will be dry in between coats very quickly.
If you had a different colour van it would look nice the same colour as the exterior too.