There is a copy of a 1934 Chester guide book in Chester reference library.
The first Chester guidebooks I saw were
1977 tiger photo, red cover (also sold in 1978)
1979 tiger photo, green cover (also sold in 1979)
1981 pair of lions photo, blue cover.
These guides were just a fold out map inside the front cover and a collection of colour photos. There was very little information inside.
The book was completely redesigned for the 1982 season, including a new style map, replacing the previous one introduced in 1971.
In 1980 a guide book to the gardens was produced.