Im sorry you lost a lot of youngsters.
Cross contamination can decimate a flock. I know.
Hoping everything goes smoothly with fixing up the new farm and moving the breeders over. You have your hand full and im sure you will make it a wonderful place for them.
I ll be moving to my new farm mid November if every thing goes well . first have to build all the coops and runs I need from scratch again . will be using shipping container as coops .fast and solidly build . new place has no trees ,it is open to the to the weather .
good thing about the new place I will be living there .so no more travelling to Sydney. all country life .
chooks man