I have finally finished the three F20 turnouts that I need for my layout. The single right hand turnout is around 500 mm long and the right hand crossover is around 750 mm.
The turnouts are constructed from flat bottom rail soldered to my own custom etched chairplates on PCB sleepers. It took around 6 months to draw and etch my own chairplates and then a further 6 months to construct the turnouts. I have calculated that I have soldered over 900 chairplates in total; I am glad I didn't calculate this before I began soldering!