[Mailman-i18n] English interface

[zbigniew szalbot]

Hello,

I am looking for way to customize Mailman English language files. Mark 
Sapiro advised me to create another language (like en-GB) in order to 
edit mailman.po files.

Does anyone have such language and if so is there any chance you could 
share the files (plus short information how to make them appear in mailman)?

Thank you in advance!

Zbigniew Szalbot