Mason & Hamlin- request for some information

[Tom Servinsky]

List,
A fellow tech call me today asking me if I have ever seen a Mason & Hamlin BB
without a tension resonator. Apparently there's one for sale in the
Jacksonville, FL area in very rough condition.
Any historians out there able to add some insight as to when the tension
resonator was introduced.
For those who might be interested in this piano contact Skip Becker in
Jacksonville, Fl.
Tom Servinsky, RPT