All soldering done, the 01 chassis was cleaned and primed. Then a coat of weathered black paint applied by hand (I like the thicker coat on the underframe and even if I didn't, the garage was too cold and damp to spray in).
The next day. Oh dear. I don't know why but I have shiny weathered black. Not what I was hoping for at all.
I did consider stripping the chassis back to metal but before such a drastic measure, decided to try a good waft of Testors Dullcote and sticking the thing in a box overnight to dry properly. In the morning, I the stuff had, for a change in my hands, done exactly what it said on the tin and my chassis no longer gleamed. Phew !