Break into old cell phones-the clear pieces of the screen will make either a line grating or a crosshair..
While you have it apart try to locate the teensy ac motor that makes your phone vibrate-for mini spyro these are used.
also Flat screen monitors-have a sheet of thin plastic that worh.
Buy a JETLSERS laser and when we have them in stock we add a free 15mmX15mm glass star grating.
Scopeguy Glenn Hand adds a 35mm slide wth all he sends out.