From personal experience, I'd strongly recommend you bite the bullet
and replace the whole thing. With the amount of corrosion in the
photograph, your on-board connector has got to be corroded, too, and
you've probably got a serious fire hazard.
If you replace everything, you'll undoubtedly get an escutcheon plate
with the new fitting, so the new paint job will not be affected.
Craig Briggs, Santorin #68