Yeah, I used to be able to import and modify STLs in OpenSCAD, but it doesn't seem to work anymore. It is very frustrating. In any case, the code I uploaded to this forum is a simplified excerpt of the code I used to generate my STL that was just meant to demonstrate some techniques. I don't know whether an STL generated from it would make a working box.

It seemed like a fun challenge to make a box from two identical pieces. I was more concerned with how well it looked and worked than whether it would be useful, although I suppose it could be used as a cigarette box. It was easy to add an option to my code to specify how tall the inner cylinder should be. I'm printing one now with a full-height inner cylinder. If it works, and if Thingiverse cooperates, I'll post the STLs in a day or two.