I'm happy now- the Tiffie is now back to how it was yesterday afternoon!
Except it has no gap around the canopy.
Thanks for the encouragement, particularly Magnus- I hope your own painting troubles are resolved soon!
I don't think I'd get very far persuading my wife to let me airbrush inside- the compressor is pretty big for a start. I'll show you where I spent this evening:
It is our multipurpose workshop/bike shed/greenhouse/paint shop.
OK, so I figured out that I would need to add white over the splatter to stop it showing through. So I sprayed some white into the centres of the panels that were affected by the overspray.
Then I re-painted the black pre-shading.
I think I have learnt a lot about pressures, thinning paint and control of the airbrush today. The black still splattered a bit (I think it is too thin- I started pouring thinned paint back into the pot, and it is now all too thin), but the white when on beautifully and I was able to control the line thickness and density of colour without any trouble (OK, there were a few 'splats' that needed to be filled over with denser white).
Then I re-painted the green:
No gap around canopy now!
No more overspray on this radiator!
Hopefully I'll mask up the plane for the grey tomorrow night, and spray it on Thursday.