Yes, the plywood plate is in the horizontal plane as Plates A and B in the above diagram. The toerail is not as deep as shown in that diagram.

The epoxy must be thickened so it will not run. Several types of additives may be used. Get the West Systems book for the least expensive introduction to use of epoxy.

A pretty large quantity of epoxy would be required to do the entire track. You might try just the ends to save material.

Did I miss a post with someone's track pulling out? What were the circumstances of that?