Electrolysis is an option a battery charger and some washing soda. I've done several sets need to treat with metal prep afterwards to stop flash rusting.
I'm 76 and my projects have been stop and go I sold a couple to finance my 29 coupe project . The 29 standard coupe project is coming together I've been working on it almost non stop last 4 months body is close to going back on the frame .
Folded and crimped is the way I did it on the bottom edge. I left tabs on top of the repair panel drilled to slip over the fender bolts to hold while welded. Photo of photos so not real clear last photo you can see the tabs maybe.