Here is an openscad script to generate sick of beige models. You can then export them to DXF for laser cutting. Almost all of my PCBs use a sick of beige template (from Dangerous Prototypes)
I added pre-generated dxf files for all sizes to the above and a shell script to generate them. They seem to load fine in our (somewhat picky) lasercad software. You mileage may vary, test on a piece of scrap.
I’m slowly discovering the joys of scripted CAD using openscad, I guess I just don’t like GUIs.