Bill,
No paint for the underside of the RossBed, its unnecessary. I don't get what you mean about sealing the plywood, it will have homasote over it. As far as securing the track/bed assembly- maybe a few drops of glue here and there under the RossBed, but everyone says it stays put once the area around it is sceniced. (scenicked?)
Finished painting the base coat on the RossBed for all the switches today. All the switch beds are done for now awaiting the top coat of the fleck paint, including the big daddy for the 175 X-over. Next are the curve sections.
So far, including the big piece for the 175 x-over, 80 pieces of RossBed have been prime coated. That is an average of 17 units per can of primer. 53 pieces for the curves await basecoating.