The player action referred to by Roger Waring had "sunken square head"
screws.  This leads me to believe that the mechanism could have been
manufactured in Canada.  The square recessed hole screw was a Canadian
invention, and for patent reasons was not available anywhere else until
recently.

Today, the Robertson screws are rapidly making inroads in the US,
especially for wooden boat building and other specialty uses.  As with
any fastener, only the correct tool should be used, i.e., avoid using
an Allen wrench or, heaven forbid, a slot screwdriver on the diagonal.

Responding to Brian Cather's query about "odd" pianos, the Malcolm
player he had is by no means odd, but rather typical of old English
pianos, from the two wooden action brackets and the screw-under-the-
felt capstans to the loose tuning pins.

Regards from beautiful Vancouver Island,

Jurgen Goering