Circa 10 years ago I was involved in a project helping transition it from 80s phone exchange into a modern facility built to a good spec. Getting connectivity out there was painful and expensive; at one point it was backhauled wirelessly to Skegness!
http://www.secretscotland.org.uk/index.php/Secrets/BarntonQu...
This bunker would have been the Regional Seat of Government for Scotland:
https://en.wikipedia.org/wiki/Regional_Seat_of_Government
Given that its location and purpose wasn't a secret I imagine it would have been blown to bits in any conflict.
But then, hey, Britain. We have a load of secrets that aren't technically secret but we'd rather you didn't know and would take a dim view of you trying to find out. Especially true during the Cold War (see e.g. Backbone, etc).
There was a new RSG type bunker at Cultybraggan near Comrie but, with impeccable timing, that wasn't completed until 1990!