I am dazzled and confused by the language that you use to describe the sentence. I don't feel qualified to judge. As far as diagramming it with R-K is concerned, however, I would probably just say that some words like "which is" are understood and go from there.
At one point in the past of this forum I compared my USA approach to syntax vs the British one to a log cabin vs Victorian mansion.
My approach works fine and allows for fun without precise syntactic terms. My log cabin keeps the wind and rain out.