Yep! Been there, done that.

My advice:

• Buy a 2002-2004 SLK cluster, and don't fret about the mileage
• Refer to MMZ-Timelord's gauge removal thread in order to remove your OEM cluster
• Carefully remove the bezel, needles, and gently pry the white gauge overlay off the SLK cluster
• Repeat this removal process on your OEM cluster... the idea is to simply swap the overlays
• Carefully apply the SLK overlay to your Crossfire gauges
• Reinstall needles
• Reassemble the unit, and reinstall in the car

I tried it the "proper" way (complete cluster swap) and I used a SLK32 AMG gauge cluster (I still have it, if you want a go at it).

The SLK gauges have an amber color when lit... but if you simply swap the overlays, the lower LCD screens will remain green. It's a neat look...

The only thing I could never sort out with the AMG '32 gauge cluster is the fuel gauge... it never worked, but I later found out it was because of the fuel graphs in the computer. Apparently you need Star-DAS developer mode to get the fuel gauge to calibrate... always something on these cars.