I dont know how many of these seatposts are still in use but a mate wanted his to stop wobbling so I used a brass Earth pin from a plug to make a new guide block .

it took about 30 mins to trim it nearly the right size and then with some wet n dry stuck to a bit of flat worktop rubbed it to the correct size with a bit of trial and error .
the end result is next to no sideways play ( for how long yet remains to be seen )

OK I had the help of a Milling machine but I reckon 1 hour without the mill would have had the same result .

Oops forgot to mention it needs a hole drilling too

a) isn’t brass quite soft?
b) is this the same as the Joplin guide block which leads me onto…
c) 2Pure sent me one FOC = zero faff

Yes brass is kinda soft but works well as bearings and is what the original was made of

no idea about the joplins jobbie , I was doing it as a favour for a mate

well thats great could have saved me half an hours tinkering