Many, many thanks Ian for taking the time to share that object of beauty. I will try and create something similar.
The ‘captive’ nut, bit of a misnomer if ever there was one, seems to have a wobbly life of it’s own and won’t stay still. Maybe that needs locktight as well. I’m also getting a tap and die set while I’m at it as I think the nut’s thread has become somewhat unwelcoming to all my advances.