I could have been wrong but as far as I understood it being a FAR/JAR 23 aircraft then it was ok. It was when I was researching this about 2 years ago.
I noted the JAA document lists the Metro's in the single pilot category. Not knowing the details of the Metro's official numbers I couldn't tell what was what.
Your message box is chockers, clear all the messages out. If you don't uncheck things, a copy is stored. Clear them out.
Using one of the links that Billiebob provided, I would contact Air Atlantic and see what they have to say. They are a TRTO and they should be able to advise accordingly.
Remember, what was ok 2 years ago may not be these days. Hence it is vital that you get the up to date info and don't rely just what some PPRuNer says.
If no joy, I would contact the CAA again and quote the documents you have used to get your info. Then ask your specific questions.