I'm considering a rewiring project

I'm with Joe. There was just a discussion of "best wiring" over at YB and American Autowire got a lot of good comments. There are many ways to go about this. In my case, I cut and filed a simple metal cover same size as the old bulkhead connector, and punched a hole / grommet in the plate. It snapped in the hole using the same gasket / hardware clips as the connector, so no hacking of the car body at all.

If I ever need to pull it back out, any connector on the bay side of the harness should snake right back through the bulkhead hole.

In my case, I scored (cheap) a partial Painless harness some time ago, and did a partial rewire / repair of the car. Now what I'm working on (not together) is a new / open box EZ harness. They use exactly the same fuse panel as Painless.

I REALLY don't care for the relatively poor documentation of either EZ or Painless. I recommend if you use one, "sit down" and do a continuity check and build your own diagram. There IS NO diagram of the harness in the destructions.