Roy, many thanks. Charles Frederick was my g/g grandfather. I've managed to do everyone descending from William Mark, but am stuck at him. The Ancestry website shows his marriage to Mary 1811, but only the 'general' record - that said, it gives the parish name and film no. Now, I'm quite new to all this - would there be a way of accessing that record without having to travel to Brighton? (pathetic question I know!).
There are still a few Bruntons in Sussex, 'my' lot moved to Lambeth in 1880's, thence Mitcham.
Many thanks, Steve