I am afraid I do not know if it can be purchased online. I believe Flamingo Park/Land things do crop up sometimes though. I have had the guidebook since 1974 - it contains a very fatuous, politically incorrect statement about the zoo's female visitors.
The "Yorkshire Post's" critique of zoos in the county began around Easter 1984 and was accompanied by a photograph of an Orang at Flamingo Land. Unfortunately I do not have a precise date for the end of the exhibition of Orangs.
I presume the Arabian Gazelles died out. I can remember only two at the zoo (or at least no more than two at any one time), kept on the site of the original Lion exhibit. I have previously posted a photograph of them taken in 1976. Of course at that time Dudley was well known for its Arabian Gazelles and like Flamingo Land it was a Scotia zoo, so presumably they had been transferred from there.