Excalibur stock with QD sling point

Sillybutts has done a great job with Excalibur. However, there aren't great ways to attach a sling. You can use a picatinny attachment near the front to for a sling point, but there aren't any good options for the back of the blaster. This updates the stock with a QD point on the right side. These cups also include anti-rotation posts to prevent your sling from twisting. Use the same print settings and orientation Sillybutts suggests when printing the parts (5 walls, 20% gyroid, 1.5mm top and bottom shell thickness). No supports required.