It can be useful to have the +5V option in your cabinet. These are not that expensive to buy, but on the other hand really simple to build.
Unfortunately there are no building instructions for this module, but at least you'll find the schematic, some photos, and some comments.
The finished module mounted in a low cost Doepfer cabinet.
Another module mounted in my second low cost Doepfer cabinet.
That's it! Simple and neat!