[B. Dudley]

That screw does not have anything to do with the shield. You can leave the screw or take it out. I would just pull it.
The shields are pretty much all the same size, so you should not have to do much inletting work. The bend of he shield may be a bit different and you may need to tweek that some.

What I do is glue the shield in with a strong glue or epoxy. Make sure to sand the back side of the shield so that the glue will stick well. After the glue sets up, drill out the holes for the brads and put them in. I never reuse the original brads. I put in new small brads and just file down the heads flush with the shield.

The factory only nailed the shields in with no glue. But brass corrodes, and that is what pushes the shields up off he wood is the corruption on the back side of the shield.
Gluing holds them in better, and putting the brads back in maintain a factory look.