Chris and
Mark: Thanks for the positive comments, they are always appreciated.
Turned metal effect round 2...
(Actually round 28 or so, but who is counting?)
Ok, here is my latest attempt at replicating the Eindecker's metal work:

I wasn't happy with the version I showed earlier in the process, so I stripped the parts down and took another shot at it. I played with a number of paint combinations on some scrap plastic, eventually narrowing it down to two options. The first, which I thought looked good, was using a base coat of Alclad Dark Aluminum, and hand painting the swirls using Mr. Metal Color aluminum. After some light buffing, the aluminum blended into the surface, and the combination looked convincingly metallic. I opted against this because of the fragility of the Mr. Metal Color; I tried a clear topcoat to protect it, but since so much of the effect was based on the differences in reflection, the constant sheen of the clear coat killed it. I wasn't comfortable leaving it unprotected, so I opted for the runner up, which you see above.
This version relies on one of Alclad's "special" shades, Airframe Aluminum. The Alclad special shades are highly transparent, and rely on their undercoat for the finish properties. Typically, you would spray a gloss black base beneath Airframe Aluminum, which results in a shiny, polished metal appearance. In this case, however, I started with a base of matt Tamiya Neutral Gray (XF-53) which gives a dull, weathered aluminum presentation under the Alclad. For the contrasting swirls, I used Mr. Color Off White, which has a medium glossy finish, providing contrast in both color and reflectivity. Unlike my experience painting with the Tamiya shades, it was quite easy to see what I was doing with this method.

Overall, I think the results are a bit of a mixed bag. My brush painting skills are not impressive, and certainly impacted the final appearance. In places where my paint coverage was too light, the swirls can get a bit lost under the Alclad, resulting in a very subtle effect. In other places where I put it down too thick, the extra dimension takes away from the illusion a bit. Perhaps the 1/32 Fokker machinists laid the aluminum on a bit too heavy in those spots. The overall appearance is metallic, albeit a generally dull and oxidized metal, swirls aside. I had the most trouble painting the cowl due to both its shape and the flexibility of the resin (lovely though it is), and in fact have stripped it again to make another attempt. More swirl painting for me...
That's all for now. Comments, questions, suggestions are welcome.
Chris