Oops- my bad- in 1919, WRA first offered the raised ventilated rib as an option-and std. rib until about 1950 on the Black Diamond and Pigeon Grade Trap guns--I have a Model 12- 12 gauge nickle steel field grade made in 1921 (by Madis sn. records) and it is a "money gun" 28" full choke- by "money gun" I mean that it always performs "right on the money"- and to have Simmons and crew install a ventilated rib on it would be akin to giving Dolly Parton a breast enlargement operation-

"The field is the touchstone of the man"..