ok here is the update:
I managed to get the newer display unit to check the ports
(this is a unit thrown out by mitsubishi as a faualty unit - they say that a client complained that it had a constant buzzing sound

)
Any way , i hacked away taking the middle console out and found my way to the RV unit display, unscrewd it out and .........
same plugs and port as on the new and old very nervously i un plugged the old unit and plugged in the newer unit ..it fit like a soft leather shoe!!
only problem i have en-counted is the metal bracket that that holds the units in place needs to be smaller and the original will not work.
so i am driving with a wobbley console today , unitll i work out my plan
will up date with pics a little later , but at least we have clarity at last , the blue compass unit is plug and play off the old unit

and best of all no buzzing sounds as yet!
