The original over center latch stopped working properly and I flew for 10 years with a piece of brakeline looped through the latch to prevent it from blowing open on takeoff.

I removed the old latch.

I made new brackets and mounted camloc receptacles.
Showing the underside detail of mounting the receptacles.
I then flush riveted a piece of aluminum, with edges for strength to cover the original holes.
I used MicroLite to fill the holes.  Sand and paint and you are set.  I know, the paint doesn't match.  I'm repainting the cowl in the near future.