“Here’s a brief explanation from “MrCan” Tony Soderman:

The History of the “Special STRAIGHT GRAIN” (like all early Comoy’s) is murky at best! Special STRAIGHT GRAINS were rarely available and were offered with the same frequency of Specimen Straight Grains (generally regarded as the “rarest pipe in pipe-collecting” as only one in every 10,000 Comoy’s became a Specimen). Also, much like the fabled Specimen, Special STRAIGHT GRAINS were NOT included on Comoy’s Price Lists! (They were not distributed with other Comoy’s but were held at the factory and were available upon special request to retailers.)”

Credit: Pipedia

This pipe has the original stem — these pipes didn’t get the 3-piece C logo on the stem.
Estimated era: 1950s to early 1960s.