There is no evidence of previous holes on either side of the panel.
Anything is possible on these cars but unless the fender is a replacement, a chrome strip was installed at the factory. Even filled-in holes leave some evidence of location.
When my car was painted some years ago, the previous owner removed all the chrome.
The rear fender had no strip and no holes could be seen.
After getting a new strip (an adventure in itself), a friend and I got ready to drill new holes. While probing lightly with a punch tool, we discovered the original holes under the paint. A slight push with the punch and we had the original holes exposed in the correct position.
The holes are small and easy to miss. Before going in with a drill, one more try may be worth it: line up the piece and lightly probe at the location of each hole. Maybe the holes are still there.
Richard M, NYC