A little note on wood. As someone previously mentioned the actual veneer is very thin.....something like 1/32". Sanding is usually futile. To add to the problem, Pagodas used straight grained European walnut. Walnut itself, whether it's straight grained or burled, is the WORST wood to use for outside or in a car because it fades extremely fast. I've never understood why walnut was used on so many cars of this era. Regardless, the point here is to say that even if the wood survives a light sanding the sun fade will have gone through the whole thickness of the veneer. To get an idea of what color the wood originally was look at the areas that tuck under the "A" pillar linings. Often times these areas will not be sun faded, and are a good reference to what the color should look like.
Color.......Mercedes never ever stained the wood. The color was applied simultaneously with the top coat. Essentially, the finish was tinted dark walnut. If you'll look in the Pkw-Ausstattungen book (Passenger car interior appointments book) you'll notice a foot note at the bottom that says "Alle Holzteile in Nußbaum dunkelbraun gebeizt". (All wood work finished in dark walnut brown). This applies to all Pagodas. Bear in mind that there are urban legends, or rumors, that darker colored interiors had lighter wood, and light colored interiors had darker wood. That's not true in any sense. Otherwise Mercedes would have noted something like that. So, never stain the wood. It will never look like it's supposed to.
Finish...From production start to production end Mercedes used a tinted nitrocellulose lacquer. The finish was never a high gloss. Always a semi gloss/matte finish. If the wood looks like a piece of glass, then it was refinished incorrectly. Granted, there are people that prefer a high gloss, and that's fine. I'm merely stating what the cars originally came with. Some of the grain should show through.....it shouldn't be completely smooth.