These files are based on acrylic components sent to me by Jersey Jack Pinball. I remodeled them for 3D printing and am sharing them here with the expressed permission of Jack Guarnieri.
The parts are installed in front of the monster faces to stop pinballs from falling into the hole when the monsters are raised. They should be printed with transparent filament in order for the strobe light to remain effective.
The three left creatures use the standard part whereas the Warg has a special part with a notch for his nose. Installation requires removal of the monster mechs. Use #8 1/2" wood screws to attach them.