The guides are, yes. I started trying to find them, as my father had left me a 1966 edition and I was interested in how the place had changed. Last week, we both trawled the second hand book shops in Colwyn Bay and Llandudno yet - surprisingly - ended up finding what we were looking for on Amazon :-)) I think one reason for the guides' value is that they stand as independent testaments to how Llandudno wanted to be seen. The hotel ads, in particular, also mark the incredible changes taking place in society following the second world war.
For instance, in 1955, when the rest of the UK was only just starting to acquire TV sets, the Imperial, among others. boasted 'large screen televisual theatre using projection television'. I can only imagine the cost involved. And taken with the contracts which Dave has managed to acquire, we start to see an image of a sharply divided society, in which some people had made a lot of money during the war, while others were probably little removed from the breadline.