Heureka! With your help and this page: http://www.ourivesariaportuguesa.info/marcas1984.html" onclick="window.open(this.href);return false; I found out that it's the bird looking right after 1983 and zooming into the picture I found the 835 digits in the small right mark. But I couldn't find anythin...
Olá! "Recordação de Coimbra". Isso já sabia... My curiosity was more about the hallmarks. As I don't find anything similar. They are only a square milimeter each. The shape of the smaller one signals Porto. I would like to know what the box is made of and how old it is.