I finally got around to searching out a turning tool which would fit my second Roller Box and finding a workable insert, this is a short clip of it on my Myford Super 7 reducing a 100mm length of 16mm Stainless bar down to 5.2mm in one pass -

https://youtu.be/nvenVLrdxLg

Roller Boxes are in common use on CNC and Turret Lathes but they are also very useful on manual lathes with power feed :D