it was written by mike d'abo and was his first hit with manfred mann. it was to have been mr jones, but it was quickly realised that the song might have been referring to the newly departed paul jones, so it became mr james.
D'Abo's first big hit with Manfred Mann was "Semi-Detached Suburban Mr James". It was nearly recorded with "Mr Jones" in the title before it occurred to the group that it might be interpreted as being an implied reference to Paul Jones.