You can click here and scroll down to Schaff, Adam. There is a list of years that the pianos were manufactured. Following each year, there is a serial # XXXXX the first piano built for that year. For the year 1916, the first serial # XXXXX XXXXX For 1917, the first serial # XXXXX XXXXX So, #42244 would have been made in 1916.
Hope this helps!