William Ross, received a British patent in 1893 that covered this iron—the first spring-face iron ever patented.
There is a hollow cavity behind the face of this gunmetal head. Over
this cavity is fixed a thin plate of steel, which forms the striking
face. The cavity behind the plate, which is held in place by the three
large bronze "rivets", allows the face to move freely, to act as a
spring to impart added distance to the ball. At least in theory...
The shaft appears to be original, and the grip is an old replacement, but fits the period well. The back is stamped "Poss Patent" in a circle but enough of the lettering remains to make a positive ID. The spring steel plate on the face is evenly pitted, as shown in the images, but still presents quite well and is no worse for wear.
TCA2: V2, p413