Our spa controller wasn't sealing properly and it turned out the sockets that accept the screws to hold the two halves together had snapped off on 3 of the 4 corners.

There was a bit left on each of them which I used as a guide to locate a new printed socket to replace the broken ones. Trying to describe this is pretty tricky so I've included quite a few photos.

I doubt the STL will be useful to anyone (unless you've got a Hurlcon Pool / Spa Controller) but I hadn't come across the idea before and thought I'd share it.