And now, after 3 years, to come back to Hans D's other question, Who was Sonja F.

I have copied the liner notes of the original 1973 LP to my page Kate's 1st album. In these notes Lionel Kilberg writes about the song:

Dear Sonja, please forgive me. In 1963 or 4, I received a telephone call from a voice that identified herself as Sonja Fromerova. She was a friend of a friend who needed some information. Her name and her voice inspired this lyric, which I showed her on our one face to face meeting. She then was to leave the country for Canada.

It still makes you wonder: What has become of Sonja...?