I've got one similar to that, SRS. Mine hangs on the wall above my bed and under the shelving. It holds electronic and electrical bits and pieces. The "selection boxes" go on a bit of the shelving above it. I've got 2 pipe cutters (15mm and 22mm - UK domestic plumbing commonly uses both these sizes of copper pipe) a different type to yours though. They live in the top section of the toolbox in my shed. PTFE (teflon) tape lives on one of the shelves in there with other tapes.

I must get round to tidying up my desk and the top of the unit in the middle of my floor soon. Both are littered with things but other than that, I've managed so far to stay quite organised since doing my shed last year and some sorting in my room early this year. I know where to find most things.