Dave,
I’m not sure that I’ve read or heard about most of the Grade 3’s having cocking indicators, maybe I forgot.
I looked at the Grade 3’s that I have and it seems you are right like usual, they all have cocking indicators except I have 1 16 gauge and the 10 gauge magnum that do not.
This 3E 16 is in the 436,000 range and was shipped in 1936 to George J Ellis Drug Company of Glasgow, Kentucky. This gun has single non selective trigger and one of those dreaded English Grip stocks, some people fondly call these ugly stocks (straight grips)