Thanks,
I am using a new fresh image - I did for both 3.8.1 (then updated to 4.0.*) and also same for 3.6
Also no PS3 controller installed (fresh image). I did try it originally with sixad installed then removed, wouldnt scan so I went with fresh build.
First thing i did was as you mentioned - add BT device via retropie script then udev button in script.
Nothing more and test > only works in ES.
Once that failed I moved onto next steps like changing config files etc. Always one change at a time.
Also did try udev to sdl.
I will try again this evening
SOLVED:
Fresh install 3.8.1
Updated retropie script
Start+R on controller (2.67)
Scan for BT
Connected
Added UDEV rule (in script)
Mapping hack = ON
All worked!
Thank you Floob.