I can't remember where the reference is but when airspace sits atop each other, eg; At Avalon where E is over D (at say 4,500), if you fly at 4,500 you use the rules for the least restrictive airspace. In this case Class E.
Would this be the same for a restricted area? Ie; It's the most restrictive so if you are at 4,500 in pretty much any other airspace (bar Prohibited) you aren't in the R?