Radio's out... (coat hanger technique worked fine )
Self-tap screws are out...have managed to ease off the surround panel to an extent, and the heater blower switch contacts are tantalisingly visible, but....

..the coin/ash tray seems to be hitched on something behind the dashboard that I can't see , so I can only pull the surround panel away a centimetre or two before it stops.

You mentioned removing the coin/ash tray. Assume you mean remove it altogether, but I'm not clear how to do this. I can see that removing it altogether would free up the surround panel completely so I could access those switch contacts I need to test.

Any clues?