I’m grateful to Jennie Falconer, another Robb family researcher, for sending me this link to David M. Bertie’s book on the Scottish Episcopal Clergy, 1689 – 2000. Under the heading for the church of St. Andrews, in the city of the same name, we find William Robb (my 3 x great uncle) listed as the minister between 1791 and 1818. According to Bertie, the church bought a house in South Street in 1804 (i.e. during William’s period of office) and the upper floor was converted into a chapel.
According to my records, William died in about 1838. If that’s accurate, then he may have retired, or simply transferred to another position in the church, in 1818. We know that he was a chaplain to Lord Elibank, and may have taught at the then college of St. Andrews.