That's a broken CE1 cluster... "broken" meaning someone has removed the second black plastic connector and left the wires dangling.
If you have an existing CE1 cluster you should be able to move a connector from your existing cluster... they unclip iirc, which is probably how one came to be missing on the cluster you just bought.
My guess, and it's just a guess, is that the red wire might be an early early version of the Vss signal needed to drive the cruise control... it's definately an early version of the CE1 cluster since it has the upshift light.