I am definitely old enough to remember Hampstead Chess Club. My first visit there was in August 1996 at Heath Street Baptist Church, I believe.

My brother went there a lot and happened to play Chess with a composer called Heinz Herschmann many times. It was through my brother I met Heinz and played Chess with him frequently at his house on Ellerdale Road in Hampstead. He became a good fatherly friend to me and we listened to lots of Shostakovich together who we both admired greatly. Very sadly, he passed away in September 2014.

I remember Hampstead Chess Club fondly for having met Heinz. According to a Google search it closed down for the following reasons:

Financial misconduct

Leadership crisis and illness

Declining interest and membership

I of course cannot guarantee the search results are accurate. Arguably the saddest reason was the last one. Hopefully it was not because of a general decline of interest in Chess itself. I suspect it is harder to find time to enjoy a hobby with very long work hours to make ends meet. We must nonetheless be thankful for Hendon Chess Club nearby and to the efforts of Adam Raoof to help make it what it is today.