Translation of signature on family shadow box art (Characters identified: 賀壽圖 北海貝雕) Can someone provide a translation of the signature captured from a shadow box picture. My dad bought it for my mum on their anniversary about 30 years ago but they have both passed away. The family started out living in the china town area of Liverpool in the early 60’s and he purchased it from a grocer in that same area after some work to provide the grocer to sell it lol. I know they are often presented as gifts to new businesses.
Thank you
Wayne
There is no signature on the art.
Calligraphy:

賀壽圖
Art piece dedicated to the celebration of the birthday of the elderly

Seal:

北海貝雕 
Shell-engraving-art from Beihai