Hans Myhre, Norway, silver, blue and white Enamel Zodiac brooch,: length ca 4.5cm, total weight ca.

Hans Myhre, Norway, silver, blue and white enamel Zodiac brooch,: length ca 4.5cm, total weight ca.14.5gms.
This is a large and substantial piece.
I would like to add a bail to this to slide it on a chain and wear as a necklace.