Rick,
O'sheas is owned by Park Place Ent. The chips were taken out of play, but I have never seen a redeemption notice on them. Andy mentioned he picked up 2 stacks in UNC condition in Dec, I bought a BOX of them UNC from the cage last year.

The GCB may look at O'Sheas and Flamingo like they do Bally's/Paris. You can use your Flamingo Player's card at O'Sheas and though I have not taken one there, I think the markers are actually Flamingo markers. All H/R matters are handled out of the Flamingo. Not sure on all the details, but hope this helps.