This unusual mask was made in 1920's Austria by ceramics company Keramos, the artist behind this particular piece being Rudolf Podany. The object was purchase online by the owner and was badly damaged in transit - thankfully after treatment, you wouldn't have ever known it was damaged in the first place. 

 

The two pieces were firstly cleaned before being reattached with a conservation grade adhesive. Once dry, the surface areas of loss along the broken edge were filled and smoothed back to for a seamless finish, before being retouched to blend with the surrounding area.