As far as I know this was never a quad, or maybe never released as a quad at any rate. I know it exists in various other formats though. If I'm honest it looks like the US Subway has been shrunk and reprinted as a quad.
I say this because why would it say 'Theatres' when we don't use that in the UK and why would a UK quad have the US release date on it?
Maybe it's a proof or some nature? Nice poster regardless though.