If you took that boom to market a choice of mountings other than the magnet would be required, there is not always a suitable chunk of steel around to mount on so things like clamps and weights, The ball on each end of the shaft is a must to be competitive the clamp plates would be easily made by punching either a dedicated die or on something like an amada turret punch. A fluid coupling on the head and base might also be good idea.
It is nice to see such skills
these days as so many of the companies that I deal with are employing people who went on a course in using a CNC mill or lathe if you gave them a machine without a screen and push buttons they would not be able to even turn it on let alone make anything from a drawing true machinists are dying breed this side of the pond.