I ended up putting this project on hold because the Immortal kit is going to be available again, soon... I hope. I will still continue to work on known issues regarding this part.
Did it fail immediately or after continued use?
I will make note of it and upload a revised model with the inside parts made a little thicker. I'm worried it could be made too thick that it would interfere with operation of the blaster, so I'm only thickening it by 0.2 mm for now.
The other issue is something beyond my control here, but it could be the material Shapeways uses as I don't know how strong it is compared to ABS.