Wow nice clocks!
Can't help with the size as I've made my dash hole bigger to fit the 400/45 clocks from my donor.
One thing you may need to check is compatability as the Rover (1.6 engine) has an electronic speedo communicating with a sensor in the gearbox via the ECU.
There are one or 2 things you can do with the original clocks.
- Buy new clock faces from Marlin (with KK logo)
Buy after market new clock faces
Trim the bezels on the clocks you have
Colour the facia around the clocks
Just some other things that are possible. I must admit, I'm looking for something with a chrome or ali finish that I can trim the bezels with, (or new bezels if I can get some that will fit) as you can't buy after market facia's for Rover 400/45 clocks.