Just a few I found on craigslist. Not mine never seen in person.
Mike
http://frederick.craigslist.org/cto/3362099132.html
http://fredericksburg.craigslist.org/cto/3327358476.html
I think the dealer can read it from the obd-2 plug. There are companies that rebuild the clusters and some that sell parts for you to repair it. You might get some info on chevy and gmc truck forums, or duramax forums. Good luck.
Mike