Mine is a mini lathe and I made a different cover made from an unknown plastic from a copy machine cover.
I hold both ends of it with magnets and to avoid the lift up of the plastic when the toolpost comes near the headstock I drilled it near the end when fully depressed and I have put through it a metal bar (you can see it extended behind the tool post).
The near side of it lifts though and it empties the debris to the back on the cover of the lathe.
If I wish to keep it level I just use a small weight as you see on the photo.