In the early 1900s, R.B. Wilson, a clubmaker in St. Andrews, designed this spring face iron for use with the Haskell or other rubber-core balls.  Hence its Haskell name. 

According to a review published in 1903, in the face of the iron is a groove about an eighth of an inch deep, over or across this groove is a thin wrought-iron plate, securely riveted at each end. The vacant space between is compactly filled with leather specifically compressed. This gives great elasticity to the club, as it were, to which the rubber-cored ball responds in a marked manner. 

This club shows quite a bit of use.  The head is pitted from prior oxidation but has been cleaned. The stamps on the back are faint to not there, as shown in the images.  The 39" shaft and sheepskin grip are original.

Another example of Wilson's "The Haskell" iron that the auctioneer has seen is in the USGA's collection in Far Hills, New Jersey.  There are just a few of these out there. For more info see, TCA2: V2, p418.

The shaft and leather-wrap grip are original.

This club is shown bottom right in the accompanying group image.