I guess I own a similar mill and went with Allendale for my glass scales.
GS500-120 Slim Glass Scale - 120mm Reading Length
GS500-170 Slim Glass Scale - 170mm Reading Length
GS500-370 Slim Glass Scale - 370mm Reading Length
Ordered matching protective covers as well.
More or less it has been an easy installation,even for a plonker like me.
I hope the pics help.