HI all
Cracked it....cant believe I missed this:
As part of the usb debugging enable...there is (what I would describe as a hidden menu) down the page which if tapped (the icon) gives options under usb...selected 'file transfer' and all came good! Oddly nobody on any forum , android or otherwise had even mentioned this....perhaps I'm bit of a dummy...or there's an assumption that we know this stuff without any help or education.
SOLVED.
Look good for the next few years