I can see small transparency dots in the logs. Was that intentional? If not, I'll suggest a solution...
1. Make a selection of your UV
2. Create a new layer
3. Fill it with white, and set the opacity to 1%.
4. Make a blurry outline using any color but black and place it beneath your UV map to prevent leaking.
If you need to check whether you have pure black (#000000) inside your UV map, use an eyedropper or extraction tool and view the hex code. If it is (#000000), then you'll get the transparency again; otherwise, you can be sure that this minor glitch is gone.
I hope that will fix it.
Other than that, it looks pretty neat and it reminds me of Lincoln Logs. I do enjoy that peep-hole idea. Good job!
