This enclosure was modeled using OpenSCAD. The model is partially parametrized, meaning you can adapt the parameters given at the start of the file and an enclosure will be generated to fit your inner volume, holes, material thickness etc.
The script generates DXF for laser cutting.
I will probably generalize this model further whenever the need for a similar enclosure arises.
See also the OpenSCAD source code for more info.
NB! Requires openscad-2010-01-31 or newer (for project() and ceil() functionality)