If you are looking for an easy way to fill the bulkhead instrument holes, here is what I did when my compasses died:

Get 2 of these for each hole: http://www.beckson.com/cvr.html

They are sized just right; I got the light grey plates.

After cleaning/sealing the area where the hole was, I mounted one of these places on the inside, and one on the outside. I had to file and reseal the bulkhead a bit for bolt clearance.

Then I just through-bolted the plates like a sandwich with the bulkhead in the middle, using 3M sealant.

Finally, I mounted my new Tacktick micronet instruments to the outside plate directly. It looks great and only took half a day to complete. The plates are so cheap that I bought extras so if they ever start looking weathered, I will just change them out. With the Micronet instruments in place, it almost looks like it was meant to be.

-dan