Does the hospital still exist? I was born in it.
No, it has been closed for several years. About two years ago demolition started followed by the construction of over four hundred houses. They're still building but the site is more or less complete.
I wouldn't normally post here as I'm not Service, but your post is a few days old hence my two penn'orth.
Google Street View
FWIW, my grandfather served at Halton in WW1 in the RFC transferring to the RAF on 1.4.1918. He remained at the Camp until 1924 as a civilian instructor.
I was born locally and attended the primary school opposite the main guardroom.