On my layout I have joined MTH Real Trax and Lionel's Fastrack. I need to fabricate a crossover to enable a K-Line Super Streets trolley line to cross MTH Real Trax 042 curve.
I know there are adapter track sections to join Real Trax and Fastrack with tin plate track. I would like to adapt other brands of switches to Real Trax for which there are no adapters. The most significant problems I find are differences in the height of the roadbed / ties, and differences in rail height.
If you have joined unlike brands of O-gauge sectional track, please say what you did to make it work.