I just took apart my AJ, the one from the flea market that was missing half an arm, and noticed he didn't HAVE a post in the pelvis. Guess Mego really ran the gamut with production changes. Looks to be two halves bonded together, rather than posts.
This pelvis looks much like certain 1980s lines I collect...I bet with a good CRACK it would fall in half. (For repair and custom reasons of course)