So another "first world problem" here. As I wrote I finally succeeded in gluing things together. The magnetic door works. The problem is that it works very good. It's actually hard to get a fingernail between the door and the case!
I guess the ideal would be a kind of groove where the door meets the case. That way I could easily remove the door. But that would mean filing away the anodizing and leaving a blank spot. I guess I could paint it black though, might look ok.
Or I glue a kind of "rail" or something to the lid. Something like a 1mm line of glue or something. Just enough to pull off the lid.
Any other ideas? Suggestions? Should I just stop cutting my fingernails?
You could always carry one of these around...

I would grind a small slot at the bottom and paint it or use something like THIS or THIS