Well, what a long time it's been...
I finally decided that I could no longer put up with the crappy old moulded earplug monitors which stopped being monitors years ago and are now not even joined by the long-frayed cable.
Spoke to the lovely Nigel at Audiofit a day or so ago and he confirmed that the Puretone set up that JackSnipe used and recommended is still available.
So I trotted off to get my ears impressed at lunch time and the distorted great lumps of silicone are now winging their way to Puretone to be turned into non-talking, full shell ear plugs as opposed to the canal-tip type I have used previously.
Once they have confirmed that they can make the separate monitors on a short cable with a right-angled plug, then they will become, as if by magic, all singing, all dancing talking plugs, hopefully in time to keep the Welsh Wramble route instructions inside my ears rather than bouncing round the hills and valleys of the principality from my in-helmet speakers.
And that only took 4 years and four months