The face of this iron consists of a thin piece of spring steel
riveted in six places to the perimeter the head. In most instances the
head is hollow behind the face, as described in a 1902 Golf(NY) review
of this club, but an early UK ad for this club described the head as
being filled with gutta percha. The US catalogs and ads for this club
never mention gutta percha.
Spalding introduced spring-face irons by 1902. This example has its
original 37" shaft and its thick, cloth-backed india rubber wrapped green grip likely installed by the original owner. Such grips were often after market additions which make them quite rare today. The Spalding cleekmark has pretty much been worn off the back of the head, the result of the owner cleaning the head with emery cloth as was the custom back in the day. However, the owners initials "C.B.W" remain. To him or her, that was all that mattered!
For more about Spalding's spring face irons, see TCA2 V2 p415