Operation Wolf Gun

So I final got a good pcb for an operation wolf I picked up and am not
having any luck with the gun registering on the screen. I've tried
cleaning the monitor, glass, and bezel and both turning up and down the
monitor brightness. No luck. I opened up the end of the gun and found
that the small lens inside the barrel is all cracked and chipped. This
definitely could be the problem so I was wondering if anyone may have a
replacement one of these they could part with. Also, does anyone know
how I could test the pcb inside the gun to verify that the opto is
working? Thanks.