Hi Biggs, yes the existing nut is "screwed" so to speak! so I am looking to find a replacement.
Hi Guy, I had thought of that but there is little space - perhaps one thread worth. You have got me thinking though, if I cut a small thin strip of steel with the right size centre hole, then it may be possible to draw it up using a new nut.
I tried a spare Weinmann brake nut this morning, but it is the wrong thread.
I will have to look for a knackered symmetric lever on
eBay and see if the nut is usable, as the rest of the lever/assembly is in lovely condition and I like the way the levers are lifted above the downtube.