Hole behind door striker

I've got a 1990 200tdi Defender which has trouble with the drivers door closing well as it was too low down by a long way. With all the repeated banging, the door striker had come a little loose so i thought i would replace completely. Took it off only to find this waiting for me which was a nice surprise.

Im not certain how this panel should look like but i dont think they rolled off the factory like that so im keen to do something about it.
Has anyone come across anything like this and what recommendations would they have?

Any advice appreciated.

Yrm do a striker post repair panel, but it's more designed to replace the bottom part that melts away (where the seat box bolts to it) It might reach up over the striker, but i can't remember how high it comes up.

I cut mine off about 20mm above the lower of the 2 pan head screws.

You are only replacing the outer skin of aluminium with these though.

The Yrm one should fit looking at the pictures on web site
https://yrmit.co.uk/product/2-3-door-2mm-aluminium-strike-plate-repair-section-lr-defender-series/