The Final Update:

We had gotten 2 non-luk clutch kits that ended up being the wrong clutch & backplate, even though they were labeled for Crossfire & SLK.
I had life and medical bills keep me from fixing this sooner.
I ended up bringing my Crossfire to Hudson Auto Center in Hudson, WI where they discovered the clutch and backplate were the wrong ones.
BIG THANKS TO Rob from @NeedsWings for helping them find a NOS (new old stock) clutch kit!

My Crossfire is back on the road again, and the clutches & backplates are all discontinued for our cars. I got to learn this the hard way.

If anyone is up to the task, I'm throwing around the idea of custom flywheels to convert our cars to a different clutch kit (like a chevy style that's super easy to find), but for now that's a pipe dream until I get in a better place financially.

Fun Fact: I have now taken the 6 speed out of my car more times than I've changed the oil!

Edit:Just to elaborate a little... The difference between the clutch & backplate I had ordered vs the correct ones is just a simple thickness. The ones I got were for some year of i4 Mercedes and were just a little too thin, even if they looked correct to the naked eye. This caused the slave cylinder to over pressure and explode after a few pumps of the clutch petal because it was trying to extend into the extra distance caused by too thin clutch & backplate spacing.