Laser pointer for K40 Chinese CO2 Laser

An adaptation/improvement on http://www.thingiverse.com/thing:53301

for my K40 cheap Chinese laser. This one is modified:
1. Clears the hinge/lips on my door (mine has a folded metal flange that tried to dislocate the original)
2. Steps back behind the mirror
3. Has a positive stop and a setscrew for angle, and has a spot for a ball-point-pen-spring instead of an external spring.

Like the other one, when you close the door, this lifts out of the way of the burning beam. Reme