If you don't get any responses, I would advise you join the PY (Pontiac) forum and post there. I know several guys there have '57 Pontiacs.
Pontiac - Street - PY Online Forums
Best of luck. I have always liked the '57's.
Yes, I am a member there and did some posting with responses. I always try to gather as much info as possible from whatever sources are available, before making any decisions. Thanks.