Does anyone have the Auto-5 book that details the Serial #'s and years? I inherited an Belgium FN made, Auto-5, Twenty. Serial # has an "OZ" followed by "45124" below.

I looked on the Browning website but I don't see any reference to the "OZ" part of the stamp.

Just curious what year I'm looking at here.

Need to clean it up a bit, but it's in fairly good shape.