I’m done! But not without a struggle.
I bought new screws, that had flatter heads, and used them as shown
Then I tried to put the cover on – still wouldn’t fit. ARGH.
Part of the metal box was poking out, I pulled it out (luckily with the GFCI still in) and adjust the screws to raise the box a little and pushed it back in. It fit! Then the screws that hold the cover on wouldn’t go in since they were too long, so I had to drill out the wood in the holes, ugh.
Finally – it was in and finished though. 1 down, 6 to go.
