I snagged a pair of Tektronix 604 XY displays off eBay. They are in decent condition but was a bit cautious about powering them up. The first thing I did was give the outer cases a good clean and left them to dry in the sun. The acrylic display protectors were scored and scuffed, so I wanted to make new ones.
I took one 604 on my bike to the hackspace so I could use the variac to power it up. I should probably get a variac for home… It powered up fine and was showing a trace! The replacement screen protector was cut from 2mm clear acrylic on the laser cutter. It should probably have been a bit thinner, like 1.6mm or so, but it seems to fit ok. I'll stick a link to the svg below if you want it.
Link to the svg is below. I attempted to make one with a etched graticule but I couldn't get the power quite right on the laser cutter.