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Good stuff Grant.
I've taken the liberty of adjusting the brightness and contrast of your engine pic, might save you taking another shot.
Great looking power plant Grant. All cameras compensate lighting levels to a neutral grey so if the subject you are capturing has a mostly light or white background, the camera will darken it to make the light background more grey. If there is a dark object in that white field, then it will become even darker after compensation. Avoiding very light or white backgrounds will help.
I used the "scratch to silver" technique several years ago on a Spitfire wingroot and was only partly happy with the result. It's hard not to scratch the silver off as well in the process so it's tricky. In order to give you a fighting chance, the silver would ideally be a durable lacquer based paint and the topcoat some kind of acrylic. Or, you could try the "hairspray technique" (Google it - there are lots of demos).
Crimea River is right about the Birdcage's interior colors - you're not going to find much Interior Green.
For the earliest production aircraft there was a coat of untinted zinc chromate (yellow) on most surfaces. A second primer coat would have been tinted with Indian Red (iron oxide) to give what Larry Webster labeled Salmon. The cockpit would have been Dull Dark Green.