A couple more pictures.
Firstly this is the switch end of the three-way. The check rails were basically just soldered on to the copper clad using the a set a Scalefour Society jigs to locate them. I was given some old Studiolith rail which is actually a little thinned than the current bullhead available from C&L et al. In reality the guard would probably just have been a piece of angle iron rather than rail, but it was rail I had to hand.
To give you some idea of how the lower level relates to the main layout here is a picture of the J15 with a train of vans on the viaduct. Ultimately I intend to have a wagon turntable where the Southern van is taking a track under the viaduct and into the factory.