In order to get the holes to match up one can use a hole finder, measure (like I did for the tunnel cover) or embrace the excuse to spend $35 on a Transfer screw set on Amazon. I am a sucker for tools so I went for the latter. The set have all sizes and each size comes with 6 stubs that when inserted pokes out to make dents in whatever you push towards them.
That little, very precise mark was further enhanced by using a center punch. I then drilled a #40 hole, reamed to #30 and finished up with #27. In the process I remembered I have a macro camera app on my phone and made some close ups, because I can.... I did deburr the #40 because I didn't want the cover plate to make scratches during trial fitting. Visually, the deburred hole looks horrible, but it feels smooth by touch. I might need a new sharper deburring tool.
Last step was to dimple for #6 screws and trim to allow for paint build-up.
I am very happy with the results, the old one looked horrible. I simply couldn't live with that every person that crawls under my plane, using a magnifying glass would be able to see it...
