Ok just looked, they are sine wave scales.
Do they have an additional box that came with them that they plug into or did they just plug directly to the old CNC control?
I have seen them on eBay but even second hand they are expensive.
You would probably be cheaper just getting compatible scales or using the motors encoders if it has them, if it is resolvers then might be better just to get encoders and fit to the ballscrews.
Hood
Hood