I have no idea either why the dissection of the Heart of the Sign, but I can attest to the authenticity of the frame. My sign had the exact same design, and the positioning of the sign in the frame. I concluded it was mounted off the side of the building like a paddle sign. My frame had a loop on the top for an extra cable to go up for securing on the roof. Frame is HEAVY, made of channel iron, rolled with the open side outward. Never figured how that feat was accomplished back then.
Ed.