I lived in Golders Green for many years. Not everyone is Jewish although when I bought one house the elderly lady next door came out to say hello and immediately asked if I was a Jewess. The other side, 2 men, a couple.
I also had an Orthodox family with many children as neighbours, and an older couple, the husband had the tattoo from the camps, as did many others. I never felt any different to them at the time but maybe because I was open to the way of life. I had moved there to be part of it.
Someone I knew from work lived in one of the big houses, his father had many properties which he had passed on to him. A lot of the property owners in London are Jewish landlords. In addition to this, Jewish people will live close to the synagogue, there are some large (expensive) flats in Central London, within walking distance of places of worship.
The young men who would call to collect money for Yeshiva would always look away when I opened the door. I had a mezuzah on the door post.
It isn't often that you see a non Jewish family move in there, unlike Mill Hill and Hendon which are a bit more diverse. I loved Golders Green. There have always been students and young people living and working there from all over, and plenty of Jews from Israel and other countries, some that I had originally met in Israel.