I think I’ve found George Robb (b. 1806) in the 1841 Scotland census: certainly the names and ages for the family all match. At Parkend, which seems to have been a large house in the town of Saltcoats, in Stevenston, Ayrshire, we find George Robb, 35, described as a ‘coal and iron master’, with his wife Jane, 25, son George 8, and daughters Jane, 7, and Penelope, 1. Also at Parkend are John Mann, also 35 and a coal and iron master, together with four servants and one Frances Dixon, 25, described as ‘independent’.
There was a coal mine at Saltcoats in Victorian times: it’s now disused, but apparently can be visited. If this is ‘our’ George Robb, son of George Robb (b. 1769) and Penelope Thomson (and I’m almost certain it is), then the question arises as to how he came to be managing a mine in Ayrshire, when other records describe him a writer (clerk), veterinary surgeon and man of independent means. Remember that George’s mother Penelope remarried, to retired West Indies merchant John Young, in 1813. Could it be that his stepfather arranged this posting for George?