Who is she?

I photographed this beautiful lady in London in 1973, using a large format camera with a fixed lens. Taken on a small balcony in Hyde Park Square, I could not move back any further to get her hands in the photo.

The model's name has been lost from the file. Not too surprising in that I shot this 47 years ago. However I recall that she was a presenter on a Sunday TV programme such as the BBC's Songs of Praise. A religious programme that presents Christian hymns sung in churches of varying denominations from around the UK.

Please can anyone in UK identify her for me?