With the higher grade wood, the checkering that you describe and the metal pistol grip cap, It is most likely at Skeet or Trap Grade, depending on the barrel set up(length/choke).
I can't really say about the rib. The rib story between Winchester and Simmons is less than gin clear, at least to me.

Post pictures if you can. If not, email some to me.

Last edited by Don Moody; 10/26/11 10:00 PM.
Ole Cowboy