Here's the state of things so far.
PIC 1. Last job before priming, which I only just remembered in time. The ribbing on the fin was a touch heavy, so this has been sanded down. The rudder trim tab actuator will be added after priming.
PICS 2 and 3. The Medium Sea Grey, in this case Humbrol enamel No.164 satin, has been sprayed overall, acting as base colour and primer. The underside will have some fading and staining added later. This has revealed the need for a tiny bit more filler around one of the cannon fairings.
PIC 4. The undercarriage doors before modification, showing the heavy rivets and the tabs intended to prevent the gear falling inside when retracted. Apart from being a bit rounded and thick overall, the inner faces are far too 'flat'.
PIC 5. The 'detail' has been sanded off, and the thickness reduced overall. The chamfered inner faces have been built-up using plastic card, sanded to shape, and 'troughs' filed for the gear legs. the brake lines were added using lead wire. The inner surfaces will be painted matt silver after clean-up.
Once the primer has fully cured, the underside demarcation will be masked, and the upper surface colours of Dark Earth and Dark Green sprayed free-hand. More pics soon, and thanks yet again for your kind comments.