I have a set of MPH Gen1 also, with 21106 miles on them.
I am sure we could come to a deal.
1000 and 600 clocks are the same size physically and same fitting, but the 1000 speedo has a higher speed indication and rev counter has lower redline.
Not sure if the speedo would read correctly, must try them and see
The ones with the white dials are the 600 ones in KPH
The standard ones are the 1000 in MPH