Jan Kees, I'm curious of the source of the information about the painted areas? I've never delved into the production details of the P-38 myself, and so I've been wondering why some of those skins in particular would have been painted silver. All of those gun bay and cowl panel assemblies had spot welding, since you have an inner stamped section spot-welded and riveted to the outer skin, to form the individual assemblies. Spot-welded assemblies had to go-together unpainted, with the metal skins acid-etched prior to the spot welding being done. Left bare, the acid-etched skins appear brighter and more dull than the untouched clad finishes of the original aluminum sheets, and during wartime production, it wouldn't have been out of the question to have simply left those assemblies bare metal. However, if they did take the time to primer the insides of the cowl and gun bay door assemblies, which could only happen after the spot-welding was completed on these assemblies, this would then explain the need to paint the outer skins on those assemblies silver, to cover the chromate zinc on the outer surfaces - "dull silver" paint/dope chosen simply to match the look of the bare metal as close as possible.
Other parts where spot welding was common were the fairings and fillets, where usually there would be formers that the fairing/fillet skins were spot-welded to, and some of the fairing/fillet skins were usually made from two halves that were welded together as well. These skins would also be acid-etched, appearing brighter and more dull compared to the untouched clad aluminum finishes. From the aluminum manufacturers themselves (Alcoa/Reynolds), aluminum sheets were provided in both shiny and dull clad finishes, which is another reason for panel variations.
Another item would be to darken the areas around the turbo chargers where the metal was stainless steel rather than aluminum. Something I haven't seen yet in these repaints is the oval mirrors on the inner cowls, facing the cockpit - those mirrors that were there so that the pilot could tell the positioning of the nose gear. Another nice thing to see added would be the "No Step" red-blocked markings on the top and bottom of the side windscreens.
Clearly in period photos, you can see the variations in finishes across the aircraft. In some photos, the gun bay doors and cowl panels appear bare metal, just brighter, where as in others they do appear to be so dull/non-reflective to the point of appearing to have been painted silver.
