I noticed (and it was previously pointed out to me) that there was quite a strong petrol smell when the car was at idle.

I needed to adjust the mixture screws, which are cunningly hidden underneath the carbs. It helped that I had a spare set of carbs to help get the right size screwdriver and also to get a feel for the adjustment of the sprung screw.

A little perseverance (and a few scratches) and the job is done. Needs a session out in the open for a while to tweak them properly, but they are in the ballpark.