I did eventually get that DNA analysis thing that I mentioned a while ago. It's good to see links to distant relatives who, next time I'm more in the mood for family tree research, I might get in touch with and interrogate.
One feature of the Ancestry website analysis is slightly dubiously estimating your ethnicity based on comparing your DNA to "a reference panel made up of DNA from groups of people who have deep roots in one region." This probably works better for people in places like America, rather than people whose entire ancestry basically lived their entire lives on the same street in Sheffield (and not one of the nicer streets, either). But I do get a surprisingly big chunk of "Sweden and Denmark" from my mother's side - doubtless from her father, who came from London, where I hear all kinds of inter-breeding with foreigners goes on.