Oops no update for a while,
I have been figuring out how to cut the track at an accurate angle for the small pieces in the actual crossing.
I have tried with my disc sander, but found it very tricky to get the angle that was needed, was a case of trying and discarding
the track.
There is a rotary table available for my Proxxon milling machine which should allow accurate angles, but that is a few Thousand rand.

So now I came up with the idea of milling a slot at the correct angle into a piece of wood and then clamping the rail to be cut into this slot.
Pic 1. milling the wood.
Pic 2. angle cutting with the drum sander