Yes, it's possible to make a DIY mold, but that takes a large amount of time, and quite a bit of knowledge about injection molding (where to have how much cooling, ejector pins, sprues, etcetara). So, for the low number of geeks wanting something special, that would be a challenge. It takes some knowledge to design for 3D printing, too, but it's definitely easier.
Attachment:
assy_stick_housing_asm (2).zip
Anyway, attached to this post is a zip containing a STEP and an STL of the housing. The mounting holes are in the PASV-4 position (my Stick came with a PASV-4). You may notice that the pot holes for the mounting screws' heads will have to be drilled afterwards, that's on purpose. By making a tiny hole on that spot, it's easy to center the (wood) drill. This way, there's no risk of the hole collapsing while printing (the housing will be upside down while printing). The holes in the sides for the pots, switches and jack are funnel-shaped for the same reason. Apart from drilling these holes, the printed housing is ready for use
As I mentioned before, my own housing was printed with 100% fill, material PETG.
Hope you guys have fun with it!