I'm guessing from the fact that you haven't thought of this yourself that you aren't a keen metalwork hobbyist? If it were me I would strip the door then:
The hole thats too small I would file/cut out larger.
The hole that's too big I would hold a piece of steel plate behind the hole, use the hole as a profile to draw onto the plate with a scribe the exact size of a blank to fill it, cut out and weld in the blank then re-cut a new hole of the exact size required.
Grit blast/prep the door and powder coat to the desired colour.