Having bought a couple of pairs of lever posts from eBay, these are the best 2 I have, with the correct bolts.
So, I stripped them down and gave the first one a good clean
I then realised that the post on the left had been squeezed in so far (by using the wrong lever), that my new pattern lever wouldn't fit. I've put this one aside to take to my welder to apply heat and restraighten. The post on the left cleaned up nicely, and with a tweak, the pattern lever fits snugly.
The pattern levers are far too shiny, so they will need a good scrub with scotchbrite to take the shine off.
I did the same clean up with the throttle
I do have a new throttle tube coming.