I want a NICE black center one and can trade my nice aluminum one if anyone is interested. Just thought I'd jump in here since the thread was resurrected.
Gary,
Your most viable solution is to remove the slats (no big deal, some careful poking and pushing) and have the slats anodized.
Stevehose can recommend a shop who will anodize them. You might even find a shop locally to do the job.
Finding a good 5 black slat kidney will be very difficult/ expensive and since your kidney is in good shape, the easiest and cheapest solution is what I've mentioned. The finish is perfect, like the original.
I will also add that ALL the 2800 had the silver type like you already have. So you are currently original!
The 5 black slat were (primarily) for the CSL's and found in 3.0 CS/ CSI's.
Hope this helps. Sometimes less actions provide more results!
Keshav
Before and after anodizing pics!