Hello Hugo,
It is difficult to tell if Keturah Davies was next door to Henry Davies and family. The census shows the list as Gay Terrace numbers 1-3, then Orme's Head Cottage. As advised, numbers 2 and 3 Gay Terrace were occupied by people with the name of Davies. It looked to me as though they could be related to Henry Davies but without further research, it will be impossible to know for certain.
I remember Madoc St in the 1960s, where was the tailor's shop that the Davies family had? Do you know the name of Mr Davies? I have seen the name Keturah used for girls in the 19th century. The others who were called this name had no Jewish connections.
I don't think the marriage in Radnorshire is right for them. It looks to me as though someone has found this and matched it to them but I should have thought they would have married in the Conwy, or Llandudno area. I couldn't find a marriage there. It would appear that henry Davies would have been buried in Llandudno, assuming he was still living at Orme's Head Cottage when he died in 1873.
It is scary here as the Covid virus is spreading locally but there is no mention of a lockdown up to now. There have been cases in pubs, hairdressers, hotels and restaurants, Most of these closed down for a deep clean but not all. The Police are not enforcing the regulations and never have done. In very recent times, people who have been caught breaching the rules in the early hours of the morning have been taken to a local guest house and dumped there, rather than arrested and put in the cells for the night. This means they are putting other people at risk because they are too bone idle to do what they should.
Helig