Jacked up the front left side to investigate the horrible creaks and groans when riding over speed bumps and found the engine under tray badly cracked in two places (front L/H/S, where the noise was coming from...). I’ve made up two metal plates to repair the cracks and secured the tray to the wheel inner skin with an extra bolt, lastly I oiled the left side front quick release fastener that was loose-ish and squeaking. Result, all the nasty noises have gone (for now), there’s only one tiny squeak left, It’ll do 
Cheers ebbo

Cheers ebbo