Stan, I recall in reading up on the late Coffeeville MS. Quail hunting legend John P. Bailey and seeing that he started with Model 12's graduated to doubles, and moved to a Remington auto 12 in mid life.
It appears to be a Model 58 with barrel bobbed and a standard Poly-Choke installed.....

His detailed records compiled over 50+ years of Quail shooting note quote "highest percentage gun, Auto Remington 12"

Pictures show him with the gun in the mid 50's shortly after the model's introduction....