Ok ...... council houses from around then were most often of a simple, basic construction. What makes it easier for a surveyor is that the construction is "predictable". i.e what you see is what you get. He should know what's hidden from view, and defects tend to show themseles easily.
Importantly, it sounds like the roof has been overhauled comparatively recently. That's a big part of a survey.
I guess what I'm trying to say is - if you can't see any obvious defects, then I wouldn't worry.
Of course, no one could get away with saying it's all perfect. There will be concerns, but I'd be very surprised if they're terribly serious.
Do let us know how it goes :o)