I have at last worked out the correct wiring loom for the radio fit. There is no need to connect to anything except the Flycom focus.
This has been designed by me with no help at all from Microair, who cannot even be bothered to answer emails.
Spot the deliberate mistake in the above diagram! The backlight cable should be wired to pin 8 on the M760 plug and not pin 15. Pin 15 is the speaker pin.