“Sparrow Red” has been posted 3 times by “Q” - when the pics first appeared, some connected to the “Red Sparrow” history of the hotel you cite, but the context is / has been different. The best impression I got is that it’s an intel spot in some way with ties to other things, particularly GCHQ + also then CF related.
Yes you are correct, I think I can tie it all together. Stay tuned, I’m still working on it, getting closer.
Tom Clancy wrote a novel (Jack Ryan) involving a Russian turncoat KGB agent code named “Cardinal”. Can’t recall the title but maybe I’ll skim back through it to see if I can pick anything up.
Caveat: Clancy is one of the reasons why I keep cynical about Q being a LARP. Time will tell.