That would appear to be a rod cocker which jives with a 11,6xx SN. A few older frames were utilized on later guns though with some holes etc already in place. The pin near top of frame bar just behind knuckle joint though was only utilized on the rod cockers for the cocking cams. The pin through bar where the sculpting starts was for the check hook & was used throughout the two-hook versions as well.

Miller/TN
I Didn't Say Everything I Said, Yogi Berra