Hello Everyone, So good to see the enthusiastic suggested support from you all to even new comers such as me.
The van Gass names was changed in the Cape of Good Hope (Cape Town, South Africa) from Gass. The progenitor Johan(n) Georg GASS arrived in the Cape around April 1816. He married a Jacoba Barendina Zimmerman(n), whose father was Heinrich Zimmerman(n).
When they were married she used the name de Gass, which lasted until they had children, all four then with the surname of van Gass. Their only little girl apparently died very young. Their fourth child, 3rd son, was Johan George van Gass. He is my GGgrandfather. Direct line Johan(n) Gass (who later was seen as van Gass) - Johan George van Gass, Willem Jacobus Abraham van Gass, who is my grandfather.
Thank you for your help. Ed v.