[Allen]

I've had a few pair of those over the years, and seen that on every one. Best I can figure is that those were stamped out of a very large, multi-station, progressive die. Certain stations were changed out as needed for production and service parts.

For example, that dimple is in the door jamb of the 73-74 Nova. The "phone hook" indentation became a half-phone due to the addition of a vent hole below it on the 73-74 models.

When GM changed the dies back over to make the service parts for 70-72, it looks like they only changed the important areas, like the sail panel and quarter window. That dimple meant nothing so it stayed. The half-phone hook stayed. Some NOS quarters have the hole below the phone hood, others don't (like the one in your picture).

Bottom line: If that dimple is evident on a finished 70-72 Nova, that would tell me that GM factory quarters were used in the replacement. I don't believe the reproduction ones have that.