I put this on ebay last week, the auction closes tomorrow (March 13) evening. The back is rusty, and the circuit board has some damaged traces, but thought someone may be interested.
Not too much. You have to move a few wires in the cluster harness plug. Mark (cdnpnt) has posted schematics on how to do it. I'll try to find the post later when I get home. I did it on my 69 Laurentian.
