Chaps, thanks for your observations, the engine is a Duratec 2.0l.
I use the car every day, short distances in all weather.
Oil is clean and use is minimal, power is good and mpg is 40 (regular monitoring), coolant is ok, no loss anyway and no evidence of bubble.
Dip stick is clean.
The residue is minimal, I have cleaned the cap and will monitor, it might very well be condensation given the conditions that I have been driving in recently - I had not thought of that.
All the best for now,
Tony
