A few years ago, I bought a ready-corded curtain track from B&Q. Have no idea of the make, and they (obviously !) don't sell it any more.
It was adjustable - the actual rail were 2 "C" profiled pieces of metal which could slide to fit into the gap.
Last week, I noticed the cord was pilling ? And rather than have the pain of trying to replace it from scratch, I was able to use it to feed the new cord through quite easily.
However, my smugness was short lived, as I noticed that a clump of fibres had wrapped themselves around one of the plastic pulleys, which had jammed.
So for months/years the cord has been dragging across the pulley wearing it out of shape.
I realised as soon as I pulled the cord .... da-da-da-da-da-da-da-
There are two pulleys which are fitted into an end piece which then fits onto the "C" section.
A quick google suggests this is the badger
I can google further but wondered if anyone immediately knows of a possible source for spares ?
I suspect I will end up changing the entire endstop assembly with 2 pulleys, rather than trying to drill/re-rivet a single pulley from the assembly.