Inspired from RRC v2 and tired of the double wire microphone / display (my was very delicate), I made an internal modification.
I used the rear DB9 connector for the display and the front AUX RJ45 for Kenwood original microphone.
Better solution.
Some detailed photos:
http://www.hb9odp.ch/index.cfm?page=photo&subpage=List&Cat=25