Hello Bryce, This may be of some connection. Can you fit anything together from this. If so I will e pleased to know all the de Vos info from here to you.
27/05/1797 III – Cristian Hendrik Schrader, born this day and married at St. Peters Church 27/01/1823 Jane Spencer, daughter of Robert Spencer and Johanna Slouw. He had by her: 1) Anna Carolina Schrader, born at Colombo 05/05/1824. Married a) John Henry de Vos, born at Galle 25/08/1821, son of Cornelis de Vos and Edith Elizabeth Petronella Smit. b) Richard Andree, surgeon. 2) Sara Frederica Schrader, born at Colombo 10/03/1826. 3) Frederick Justin Schrader (who follows under V.)