I seem to remember that in another life, the Canberra cockpit was what they called Combat Pressurised i.e. half the height flown plus 2000 feet with a maximum of 25,000 feet. I also remember a few leaky aircraft that showed well over 25,000 when being flown at 45,000 ft.
After suffering 3 rapid decompressions in one week during airtests, I was very grateful for the Combat Pressurisation and also the AMTC training.
Heads down, look out for the flack