That's a nice skin 5PointOh. The rivet shading effects are definitely a worthwhile improvement.
WRT painted areas on the B-29 I've done a fair bit of research on this, including reading the painting instructions in the B-29 maintenance manual. Apart from the first olive drab examples B-29s were mostly unpainted inside and out. The exceptions to this were the pressurised crew areas, the exposed areas of which which were painted in chromate green. The bomb and wheel bays were left unpainted. Externally the gun turrets, front lips of the cowlings and the bomb aimer's canopy framing were primed and then painted aluminium as well as all the fabric covered control surfaces. The front nose leg was often painted in yellow green primer.
Also on the B-29A much of the wing skin was made of a higher strength alloy that corroded more easily, so this was also primed and painted aluminium. On the default skin you can see this as a darker area extending across most of the upper wing between the front and rear spars and out to the wing insignia. Underneath the wing only part of the area between the inner nacelles and fuselage was painted. The fuselage section adjacent the wing join was also painted this way.
Early B-29s had a different wing construction and so may differ here, I'd guess the fuselage section may not have been painted on these. Also I am not sure if all the internal areas of the olive drab B-29s would have been painted in primer or left unpainted, I've not found any good info on this.
Note modern restored examples of B-29s are not good references to paint on B-29s, particularly "Fifi". Many of these have been painted to protect them from the effects of corrosion more than for historical accuracy. The exception to this is the Enola Gay in the NASM, this shows the painted sections of the wing particularly well.
