Signs of the Times: Pianos

This is the sign that piqued my interest. I drove past this every evening on my way home from work on a free lance job downtown. I wondered: Whose Pianos? How many times was this over painted, only to have the original paint come through? And what did P.P.X.L. mean? And how long ago was advertising so simple that just stating the product type was enough? Or that pianos were advertised this way?