Tricky.
I removed my steering column in order to give myself more room to work on the instruments. I took it upon myself to paint it since it was chipping all over. I also wanted to simply touch it up, but I ended up refinishing it.
I don't know how bad your assembly looks. Mine was suffering from the aluminum oxidizing and causing the paint to flake off. I considered giving the whole thing a coat of semi-gloss Rustoleum without any prep in order to preserve as much of the original texture as I could. This might have worked, at least for the short-term, though I knew this would result in me redoing it in a few years. I opted instead to lightly sand some of the affected areas. This turned out to be a mistake; the paint had become so soft over time that I suddenly had a flat, untextured spot. It was then I knew I'd have to do the whole thing.
I know this is going outside of the scope of your question, especially if yours is still in the car. Others have reported good success with textured paint:
http://www.e9coupe.com/forum/showthread.php?t=4456&highlight=column+paint
Here is the process I came up with:
1. Completely sand the thing, right down to metal. Clean thoroughly.
2. Mix a small batch of Bondo -- a few ounces to start with maybe. Using an applicator of your choosing (I used a finger tip) dab the Bondo on, creating a rough texture. Allow it to cure.
3. Paint it with some contrasting color -- not pink or white in other words. I used the same black I would use to finish it.
4. Sand it. The pink of the Bondo will show through and this will allow you to judge where the low points and the flat spots are.
5. Clean it and spray paint it. Here is my result:
In my opinion, my texture is a little to 'big'. Perfectionists should do a few tests strips first to test the process. You should be able to control the texture by regulating how fast you dollop the filler on.
What do you think? I hope this is helpful.