Front fender issue

[DennisR]

Thought I would replace my fender welt, so duly set about removing front left fender. Did not realise that the fender was spotwelded to the nose of the apron, now I know why there is no welt on that part. The seam is showing some rusting which I would have liked to address, is it taboo to drill out out the welds, add welt and use bolts to reinstall, or should I clean out the seam best I can and use a good rustproofer.