Here are the photos.
The rudder is undoubtedly white, but compare the tones of the white spinner segment, with the tone of the cowling, and you can see why there's a question as to whether or not it's white also. Personally, I think it's RLM 65, but also note the difference in the demarcation of the upper colours, compared to that on the 'saddle' cowling over the guns, which has lead, in the past, to the comments regarding a replacement cowling (by the unit,
not after the forced landing).
The aircraft force-landed on 5th September, and another aircraft from JG3, coincidentally force landed at exactly the same time, a few miles distant. This aircraft had the white rudder and wing tips, but
did not have a white, or part white cowling.
However, it is possible that only the lower cowling
may have been painted in white, washable, distemper-type paint on von Werra's aircraft, but this is not mentioned in the RAF crash report, which noted that the rudder and wing tips were white, and the camouflage "all blue".
The spinner back-plate appears to be in RLM 02, and the blades will be RLM 70. Note that the spinner is intact in the photo you posted - what appears to be a black 'spot' is in fact reflection on the black paint, and showing more contrast through the dust and dirt. Visible through the prop blade aperture is the front face of the back plate, which is perforated, and would be in RLM 02.
The prop pitch cylinders (the 'brackets' you mentioned) were shiny, bare metal.
The engine is overall semi-gloss black, with the engine bearers in RLM 02. The lighter shade at the base of the engine is most likely dust and dirt, accumulated during the forced landing, and afterwards in the salvage yard.
Note that the underside colour (RLM 65) wraps around the wing leading edge on the main planes, but not on the tail planes. Note also the lack of head armour in the canopy.
The staining on the fuselage sides is almost certain to be as a result of engine damage, and caused by smoke and oil vapour - in the photo taken in the salvage yard, it can be seen that the staining has been cleaned off the unit badge. Before the combat leading to the forced landing, the aircraft would have been clean and relatively stain free, but probably had some light exhaust staining.
The undercarriage covers are inboard, as the gear retracts from wing root outboard.
The antenna wire arrangement shown on the model is correct. The lead-in wire from the main wire entered the fuselage via a porcelain conductor point, white in colour, which protruded slightly above the 'skin' of the fuselage.
Note that the modeller has added a central frame to the canopy (seen next to the model). this is incorrect - there was no central frame, the side glazing being in two parts, with the front section able to slide open aft, rather like the older types of Land Rover. Also, the exhausts were not silver, and the silver area above is also incorrect. This is the ignition lead group, where the wires themselves might have been a metallic, sheathed type.