Using a modest domestic grade 3D printer, the z-axis height and build plate size are pretty much spot on EXACTLY the dimensions of the Gameshell.
So if you wanted to potentially print one yourself, you’d be in luck.
That said, the stock housings are injection moulded, so you wouldn’t get the same finish, without arduous sanding, spraying of clear coat and copious amounts of acetone.
There have been a few other threads with people documenting their 3D printing journeys. Pop it in the search. 
This one in particular I am fond of, by the user @Rebusmind
And here is a comparison of the Gameshell size vs. 3D printer build plate dimensions. On a side note, the translucent resin I use is fairly expensive, like $80/500mL. But I don’t think printing a shell would be more than 100mL, so factor that into the clad factor.
I’m waiting to find out if they will release the DEOT shell only, before printing my own. Once they let me know, I may write out a 3D printing tutorial.
