Where Do I Begin?

I've decided to lay the double track section on the right-hand side of the garden first and to start at the top of the garden. The outer curve will be made up of 6 radius 5 curves. The inner curve will be made of flexi-track.
The photo shows my giant homemade compass. At the centre it pivots around a tent peg. At the outer end I've drilled two holes the same diameter as a pencil - one at the inner track radius and the other at the outer.

Homemade Compass

The second photo is of the template I've made for bending the inner track rails.

Track Template

I've started stripping down and cleaning the flexi-track from the Sandwell Valley Railway.

All I need now is to borrow a rail bender.