Hello List,  The Amherst Pianos were made in Amherst, Nova Scotia,
Canada from 1913-1928.  According to the Pierce Piano Atlas in 1926 the
serial numbers started with 22708.

The bass strings are probably worn out, although the bass bridge could
have become unglued and therefore unable to transfer the vibrations
efficiently.

The book "Downright Upright" by Wayne Kelly, has a over 1/2 page of info
on the Amherst Pianos.  Hoping this is of some help.

John M. Ross
Windsor, Nova Scotia, Canada