Where can I find the pZ189vector plasmid vector sequence?
Turns out the sequence is not actually written down anywhere. I asked one of the original authors of the plasmid (not the paper above) and he said that nobody ever did it because at the time when the plasmid was used it would have been a laborious task with little utility. Bummer :(

He also said that plasmid pSP189 is sort of the same but much more efficient and what it does, and is also more studied, with the sequence freely available around the internet.