While I was working for AoT, Dave "Macca" McKenzie the Chief Engineer had put a proposal to management to replace the PA-31 Chieftains with Doves.
I presume they would have been converted to the Riley specs, to match the Herons.
There must have been a number of low time Doves that would become available in the UK in 1987/8?
The project was knocked back when, they won the Air Ambulance contract and they were going to use a PA-31.