Hello, I did a pretty thourough search online but couldn't identify this exact model. Clearly a lapis lazuli dial but with automatic inscribed and diamond bezel. Any help is greatly appreciated !! ...  

“ 1978 Piaget Reference 12342 With Lapis Lazuli Dial” You will find a very similar watch but in yellow gold and without the diamond bezel. I know it is not the exact watch but it could be the same base model of 12P.. Hope this helps!