Hi Harri,
Sorry for my english... I translate a page from my website...
"This medal was established just after WWI by Catalan Volunteers Comitee. During the war, this comitee was in charge to recrute volunteers who'll fight in french foreign legion (colours of 3° REI received this medal). Medal was struck by firm Vallmitjana, in Barcelona: it's a dark bronze medal with roughly ribbon (catalan colors "blood and gold") completed by a gilt brooch with pin (as usual for spanish medals). Beware of copies!!! (lighter bronze and modern ribbon generally without brooch). A diplom was delivered with the medal".
You can see this page from my website but in french...
http://www.medailles1914-1918.fr/espagne.html
Regards
Marne