I offered to translate to Portuguese (from Portugal), and senky sent me the pt_br files.
The differences between Brasilian Portuguese and Portuguese from Portugal do exist, and in phonetics they are quite substantial, slightly less in common use vocabulary (mainly in casual language), but the structure of the language is basically the same (I didn't notice anything needing rephrasing).
So basically all I needed to do was to check for cç, ct and others. Did that and then used an online spell check to catch my typing errors ... and just about very word I changed was marked as erroneous.
And then it dawned upon me, the Acordo Ortográfico da Língua Portuguesa de 1990 which was a compromise between the various spellings but mostly favoured Brasilian spelling. It would not be enforced but gradually introduced.
So?? No problem one thinks, just keep the pt_br and there's no distinction necessary between pt_br and pt_pt. Unfortunately it's not that clear.
The Accordo was agreed upon in 1990 but both spellings would be acceptable for quite a long "grace period". So I learned the "old" Portuguese the Portuguese way.
As of 2016 there should, strictly speaking, be no more difference between the orthography in BR and PT. In practice however there are still quite a number of words with 2 accepted spellings.
The result of all this is that my translation (based on outdated knowledge) cannot be considered acceptable (that's my conclusion without sending my translation to Senky).
So I'm making a call for a native Portuguese speaker who is confident that he/she can and will use the official orthography (so as to translate the language files of the extension to current Portuguese (from Portugal).
Spelling is freeware, which means you can use it for free.
On the other hand, it is not open source, which means you cannot change it or publish it in a modified form.