Hi Mark, sorry it's a bit late to be making contact, I've just seen the date you posted your london Ewart enquiry.
I also have Ewarts based in London, from 1837 to date. It wold appear that they made one single leap from Scotland, however, you do wonder if they had family already established in london already! Mine seem to be in the Bermondsey/deptford area (yes south of the river). I haven't found any european connection, yet it dosen't mean there isn't one. The other reason for getting intouch,is that I was looking at your other enquiries re Wiltshire records. It's very strange, but I used to live in Market Lavington, which is next to West Lavington. If it is on any help, both Lavington's come under the sailsbury diocese, which may be a bit more "online". Let me know if I can help with anything. Helen