XB-1 Neck not flush in pocket

[Kitcatski]

Hey guys,
So I just redid the finish on my neck and it came out great. The problem I have now is that the neck fits extremely tight into the pocket, which in itself isn't an issue but it doesn't sit completely flush.
Here are some images of what I mean
https://imgur.com/a/ItWrGm3
The 2nd image shows that theres actually a small crack on the side where it is very flush (its hard to see in photos, and very small in real life), which I'm sure isn't a huge deal.
My question is how do I fix this? I'm assuming i need to do some sanding, but on what part of the neck? On the side thats already flush? I'm hoping that since the gap is so small the fact that i already have the holes drilled shouldn't be a problem.
Thanks

[Simon Barden]

Is that just sitting in the pocket or is it screwed down? If just sitting, then screwing it down will minimise any gaps. If it is screwed down, then you could try and determine if its the neck heel or the bottom of the pocket that isn't quite right, though it may be both. Also check for sawdust or raised edges around screw holes stopping the neck from sitting fully flat.

But it may also be that the finish on the neck is pushing hard against the sides of the pocket (possibly a reason for the crack in a traditionally weak area) which is also stopping it from being able to sit flush. If so, I'd think about lightly sanding the sides of the neck in the pocket area and re-polishing just to make it a small amount narrower, to see if that helps.

If it were my guitar, I'd probably try and mask around the crack area and wick in some thin CA glue. Any crack is likely to get bigger in time (though my experience with similar cracks on Strats indicates they get to a certain size and stop). As thin CA is very runny, you'd either need to use one of those very thin nozzle attachments so only the smallest amount came out, or drop some in on the end of a cocktail stick. Don't do it straight from a standard CA glue nozzle or you'll swamp it.

The good thing about CA is that it's clear and you can sand and polish it so you don't then need to add any more clear finish (unless you really want to).