It’s really not easy to find activities that practise only was and were. Most books tend to teach these along with other past tense verb forms.
New English File, elementary level published by Oxford University Press has an excellent unit for teaching and practising was and were. If you can’t get hold of it in New Zealand I suggest you prepare a text on famous people who are no longer alive. Write a short piece about each person; try to include at least one description of a couple. You should try to make sure the only verbs you use are was and were. After studying the texts and making sure students understand them, turn their attention to the use of was and were. Remind them (or elicit from them) of the use and meaning of was and were.
You can then show them pictures of other famous people and ask questions such as:
Where was he from?
Where was he born?
Where were his parents from?
Was he famous?
Why was he famous?
Remember to include some work on pronunciation. Students can then continue with pictures and these type of questions in pairs. They can finish off by asking each other questions similar to those above.