Trying to find Jewelry author's relatives

Hi All,

I am looking for any living relatives of the following authors who
wrote about the metals/jewelry field:

Louis Haas, “Art Metal Work and Jewelry”,

F. R. Smith, “Small Jewellery”

AC. Horth, “Beaten Metal Work”,

Herbert Maryon, “Metalcraft and Jewellery”

If anyone can help me get in contact with any of their living
relatives I would appreciate it.

thankyou
Charles