this is crazy. was it a straightforward mod, or did you need additional mods/resizing of parts?
It was straight forward and was something I had in my mind for a number of years. When I first got a Mitsukoshi dial I was also working on a MkII at the time and test fitted the Mitsukoshi dial to it and was quite impressed with the look.
This is a pic from some years back as a test fit, fitted crystal is without the black outside track 😁
The standard MkII dials are about 31.4mm diameter and the Speedmaster 31.1mm, the major difference is the MkII dials are flat but the Speedmaster is stepped. This means there is a minute gap between the dial and the silver spacer ring which fits between the dial and the crystal. I might correct this by adjusting the movement retaining clamps but so far I'm fine with how it looks.