Domed area under Side Mirror - Damaged or Intended? - 67 Valiant

Hi folks and happy 2022! In regards to my 67 Val Signet ... I removed my side mirror today, in prep for painting, and discovered this 'domed area' where the stud goes into the interior of the door. Is this damage from someone tightening the nut, w/captured washer, too much or should this 'dome' be there? Yours in wonderment.

WhatsApp Image 2022-02-06 at 15.28.55 (2).jpeg

WhatsApp Image 2022-02-06 at 15.28.55.jpeg