Are all series 1 Petrol Tanks Interchangeable?

Oh, ok! Glad you told me that :) Do you know what year in particular I should be looking at staring from?

Not really but at the time I assumed it was sorted for the MY97 update. Nothing to back that up though.
You could Google the recall which would give years even though it wasn't conducted in Australia.

Thanks for that info Utemad! Now I know what to look for :)