PX-10's(or the 50's equivelent PLX-10) from those days had yellow, or goldish paint on the lugs. They also had either Reynolds 531 straight, and butted tubes, or Vitus butted tubes. This could be a Peugeot, or it could be any of a wide variety of similar bikes. I suspect Peugeot though because of the blue paint.Probably late 50's, early 60's