What is the lead screw made of? There is a big difference between machining chrome moly steel and machining studding.

Best mount is one axial thrust race at either end and one powerful spring holding it in tension. This is very reassuring when you eventually chuck up your DTI, measure the backlash and have a panic attack. (Not a good idea if working in MDF though, it's about as resilient as marzipan when under load).