I think I found mine: Parker Reproduction 12ga, 28", SST. Factory choked IC/M, but actually measures 007/011. Good for skeet, and also for typical Sporting Clays courses for side by side events.

When I bought mine (off the for sale board here), there was a long discussion about those choke constrictions. Turns out they were standard on 12ga IC/M Repros. You won't have any trouble finding a Repro 12ga with 26" barrels and those chokes, but most with 28" will be choked M/F. I would have preferred DT on mine, but that's a personal deal. So far, no issues with the SST. Likewise, you might find one with a PG or a BT, or both.

You'll likely pay a lot more for a Sporting Clays Special.