Knabe/Chickering 9' ages

[Bdshull@AOL.COM]

List:

I do not know how to date a Knabe or Chickering 9'.  They appear to be
American Piano Co. era pianos.  These pianos have different serial numbers
than the standard; usually 5 digit.  I rebuilt and sold a 9' Chickering which
appeared to be from the '20's or 30's;  great piano, still very powerful
including the mid-treble;  never established a date of manuf. 

Have a 9' Knabe at a university which I want to provide accurate age info on -
s/n 10651   Any ideas?   I keep meaning to ask Paul Monochino at conventions;
either I forget to ask, or I have forgotten that I did ask him....

Thanks!

Bill Shull
U of Redlands, La Sierra U
Loma Linda, CA