Fender marker patch repair

So I bought this fender a month or so ago and I am finally getting a chance to work on it. What I have is a 70-71 fender that someone attempted a 72 conversion on. I have a couple questions...

Option #1 Slighly recess the patch in the existing opening and weld it in from the backside. I figure that will give the filler the best chance of holding by filling in the small gap around the edges...

Option #2 Weld it and grind it down on the exterior side?

Option #3 Get rid of it now as a 70-71 and find another...?