Hello, I want to put a passing siding on my small layout and I want people's advice on which number of switch to use. My layout currently is an oval using Altas 21st Cent. track. I am using O-45s for the mainline. I want an inside passing siding using O-42 radius track. I plan on the track being approximately 4 inches apart (from center rail to center rail). I want to know which number of switch will be best suited for getting the tracks that close together. Obviously O36 switches are not going to work. Would an O72 switch work? Or maybe a Ross #5 switch? Other suggestions? Thank you.