Yes you are correct that is the spring I had issues with, my concern was that there is a fair amount of pressure in the spring and I thought that it would wear the plastic down very quickly without any protection but apparently not.
The car steers great the tilt and slide work a treat without a lot of movement in any direction but I will need the cast aluminium braketry that the indicator/dip and main beam lever attaches to via a roll pin as this has broken. I have an idea that this is probably not available but is known to break, if I can't source one then I will have to make something up as sticking my finger in the lever hole to operate the indicators is not the best idea for the long term and I can't operate the dip/main beam that way.
You exploded view is the best I have seen to date, thank you for posting it as I can relax a bit knowing I put it all back as it should have been.