If you want your page layout to default to A4 size, instead of letter, just paste this into Terminal. It will copy the British resources to the (American) English location:
sudo cp[space]VERY IMPORTANT NOTE: I've broken this onto SEVERAL lines to keep the story narrow enough to read! Do NOT copy and paste the entire section. Replace the '[space]' words with an actual space character, and enter this on one line. There are ONLY two spaces in the entire string after "cp", as shown above.
/System/Library/Frameworks/ApplicationServices.framework/
Versions/A/Frameworks/PrintCore.framework/Versions/A/
Resources/en_GB.lproj/Localizable.strings
[space]
/System/Library/Frameworks/ApplicationServices.framework/
Versions/A/Frameworks/PrintCore.framework/Versions/A/
Resources/English.lproj/Localizable.strings

