I have a bunch of broken glass from larger failed plates. I will cut them down to usable (non broke) 4x5 inch size. I should be able to scavenge 10-15 4x5 inch glass plates.
I was initially thinking I would use the glass for workshop students. I think now thou that bringing my funky Speed Graphic and funky Aero Ektar lens out of retirement, might be a better plan!!