Well after looking at some of your other posts, it seems you are into rebuilding wood working equipment, and reach out when you can't get the parts or identify a problem, so I'm going to get you to think of how to solve you problem with tools at hand and little expense.
Material, phenolic or plastic from Azamon (or other cheaper suppliers).
Solution
1. File/hacksaw/straight edge/scribe using existing track as a guide, go at it remove material you don't need. Done.
Expense increases but opens other future options.
2, Milling machine, see 1. Done.
3. Cheap CNC mill/router, go at it. Done.
4. Cheap 3D printer, go at it. Done. (Note this method is about adding and not removing so it is very dedicated, but once you have one, well you can fabricate lots of things).
The solutions and methods are endless. Prior to 3D printers, the question was always, material...source. Followed by how do I remove the excess material to get what I want? From cheapest but time consuming to the fastest/easiest (requires equipment and tooling investment).
So hopefully, this gets you thinking on solving your problem (and future ones) and who knows you may go down the rabbit hole like the rest of us.
This falls under give a man food he eats for one day, teach a man to fish he eats everyday.
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