Found this in another thread. It may help...
"OK, I'm rebuilding with ScaleTrax.
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Yes, the selection of switches is limited a bit, O-31, O-54, O-72, #4, #6 left or right.
However, Ross switches have rails that are VERY similar to Scaletrax in size and shape (slightly taller) with much thicker ties.
Easy fix: 5mm roadbed under the ScaleTrax and 2mm cork sheet under the Ross switch. The tops come out even and the rail shape match is sweet.
I have a pair of Ross Wyes to mate up with my ScaleTrax."