I'm pretty new to the idea of exploring cinemas, as you can probably tell from my reports I'm mainly into Industrial sites...
I've been swayed to look into cinemas a little more though now having enjoyed a certain Pontefract cinema and the Palladium in Durham.
Just thought I'd leave this link here, not sure if people have used these before or not, but the old Gaumont Kalee year books are pretty useful. You've got a full directory of cinema's that where open at the time of publishing as well as a pretty useful guide to IDing any equipment you might find on an explore. I find them pretty interesting and useful anyway, bought myself the 1949 edition off ebay but they're free to access online... Just thought it might bring up a few leads, if not, they're an interesting read anyway...
https://archive.org/details/kinematographyea1954odha