I'm in the same boat as your daughter... my house was built in 1905.
Fascia... It's bead board... I put it 1/4" (or so) above the sound board so that ballast, coal and the like stay on the layout (the carpet is brand new). However, the bead board is pvc... I glued and nailed it to the plywood bends and 1x4s. I haven't secured the legs yet because I'm waiting for the 2 1/2" carpet/caster cups that I ordered to put under the legs and do final adjustments before I set them permanently. It's really solid right now though.