A very frustrating day battling Templot. Very useful and powerful tool but my brain is wired to work differently to it and therefore I find it hard work, particularly as I only rarely need to use it.
I started by using AnyRail and the C&L templates to give me a quick and dirty plan to work to. The downside is that you can't bend the point templates to sit on a curve.
This was then imported into Templot to use as a guide. Much swearing later I got this:
Which looks like this if you remove the background image:
The diamond should be a double slip but that's beyond me and attempts so far have ended up with the laptop being in danger of damage....