I had a pair in the 1980’s at Cleveland QLD, the cage was 3m long 2.5m high and 2m wide,
Tin covered all the cage apart from 1m from the front sides.
1st year of having them ( they were already older ) 4 babies which i hand reared,
At that time not many were breeding these and i think the tin helped hold in some heat as this was the only difference i found with others trying ( even their old owner never got them to breed )
They are well worth the effort and great birds to keep/