Interesting post. Of course, the auto ejector option came out when the other three did not exist, so we see that the most. I think, too, the options chosen were driven by brand of gun and grade of gun. My experience is that Ithacas, the NIDS, in higher grades were very likely to have all four options. I remember a Grade 5 NID at an auction and thinking I had never seen another with splinter forend, double triggers, and a regular rib. I assume most of the higher grades in NIDs were trap or skeet guns.
