Well, I'm a fan of patching where logical, and where it's much easier than the whole panel.
But in this case, because it's a multi-layer affair anyway, I'm not sure you're not going to find a whole not more nastiness where that came from.
I realize that patching would seem to be easier because you're basically removing a critical support component that's welded to multiple other critical support components (floor, rocker, bedrail, etc.) but for the cost of a new one even at 80 bucks being a lot more than just some sheet metal, I think it's worth it in this case.
I could be biased, because I sell them and don't sell bulk sheet metal, but I think I'm being honest when saying, dig into it deeper before making your decision, but I think you'll benefit from the new one.
Find out what the condition is of the striker and it's associated bits.
Good luck.
Paul