Back in '04 when I bought my 6 string Europa, I noticed this unevenness along the back of the neck and body between the maple and purple heart laminations, and sent Mica an email requesting info. She sent me this response:
The back of the neck sounds like it has some shinkage where the different woods have
moved at different rates. If the feel doesn't bother you, don't worry about it - it's very
unlikely that it's actually delaminating (only have I ever seen this once). To repair, you'd
need to send the bass here for a new top coat and rub out. We can leave the neck glossy
or make a nice satin finish on it. Top coat and rubout isn't cheap at $550, but the bass
will appear as new, and will likely not shrink as much in the future. You may want to wait a couple years before doing this, since it may have a little shrinking left to do. We wish we could keep every bass here for ten years then retop coat. It seems to take almost that long to convince those trees they want to be basses
I elected not to retop coat the bass, and am happy to report that no actual delaminations ever occurred. It seems that this phenomena is most noticable where the dissimilar wood types are adjacent to each other and move (shrink) at a different rate. I am not exactly sure if the wood has actually shrank away from the surface, or if the outer finish is absorbed into the wood. But I am not worried about it.
Kris