Ignition coil screw hole

The threads of one ignition coil screw hole has broken apart. Need help on:

1. The size of replacement insert to get. I will include some pictures. Is #10-32 same as 1/2-32 size insert? Do you count the recessed area in the thread in counting the thread per inch or whatever it is?

2. I think the DOHC cover is made of hard rubber or plastic. I put two little very small magnets to it and they did not stick. So, can the hole in the DOHC be tapped itself with threads to put in a helicoil. Pretty sure screw cannot be screwed right into that surface of the hole if threads can be put in it right?

3. Please take a quick look at Sky Geek website for Part#: NAS1329A08-75. Can that rivet if right size be used? Hope can push firmly in. I am looking more at EZ-Lock inserts, but nee to know if I can find the right size.

Think that is it for now. Thanks!

P. S. Do you have an email address I can sent the rest of the pictures to. Cannot get them to upload.