http://www.pianoworld.com/knabe.htm arround 1913...
I have one that the serial number is close and it was built in 1833. Not at home so I don't have exact serial #, but this seems close. Do you have any idea how much it is worth or any on in the...
According to this.... http://www.bluebookofpianos.com/serial1.htm#WILLIS%20&%20SONS your piano was built (roughly) in 1910.
It should be around 1974. (For References see Related Links below)
According to my copy of the Pierce Piano Atlas, the Baldwin piano with serial number 127398 was manufactured in 1954.
try this list for serial#'s & years www.pianoworld.com/knabe.htm