Dear MMD,  As far as I know, Keith Prowse of London never actually made
any instruments although their name appears on many.  They imported
many different types of piano to the UK from continental Europe and
badged them with their own name to get round the political difficulties
of the day.

In the late fifties, when the War was not yet forgotten, I was asked
to inspect a coin-operated cafe piano carrying the Keith Prowse,
London, name on the fall.  The unmistakable 'LH' logo of Ludwig
Hupfeld, Leipzig, was clearly cast into the frame.   The elderly couple
who had owned and loved the instrument for over thirty years were
horrified to learn it's true origin and promptly gave it to me to get
it out of their house !

I suggest the owner of the mysterious barrel piano carries out a search
inside the instrument.  There will almost certainly be some clues as to
it's true origin.

Richard Stibbons
Cromer England