I haven't tested all of these yet. The shorter ones are just shortened versions of the regular rail. The curve was generated with a different OpenSCAD file.

A replacement rail for the board game Pitchcar I created in a hurry in OpenSCAD. It might take some adjustments and fine tuning since this is a fairly small part. There is an up and a down side to this rail. They are both tapered, but one has a longer taper as I wanted to have options when trying to get the rails inserted into the tracks.

215mm length, 3.5mm width (the slots in my tracks are 3mm and the tapered ends are supposed to be 2.75mm.

Short (127mm) is for the 45 degree sections from Extension 2.
Straights are 215mm.
Curves are 258mm.
Medium is 160mm (I can't remember which track part this goes to right now).
Exp 6 medium is 109mm.
Exp 6 short is 53mm.

All these measurements are in the OpenSCAD file

I tried https://www.thingiverse.com/thing:2008009 but the taper did not fit well in the slots on my track, so after fiddling with scaling of that model, I decided just to make my own, more primitive one that met my specifications.

Printed from PETG with all walls and no infill, these seem flexible enough to be used in the curved sections without an issue, but it may be difficult to fit them on the print bed. I printed the long straight sections diagonally and could print a handful at a time.