Here is a very well preserved steady rest for an Atlas lathe. The shop it came out of did have an Atlas lathe not sure of the size. I did a bit of searching on the internet and based on the numbers in the casting I think it goes to a 12 inch lathe. A quick measure of there the rest would sit on the ways to the center of the circle is about 6 inches so a 12 inch lathe. Let me know if I got this wrong. Otherwise it is in great shape. Just minor wear to the brass tips.