Mills was the most prolific designer and manufacturer of early
aluminum head golf clubs. He created The Standard Golf Company, a
division of The Atlas Works, to produce his clubs which are referred to today as "Mills" clubs.
This Mills MSD 4 Model was produced in the early 1900s as a special
spoon. Among other things, Mills sought to eliminate the use of irons, so the MSD 4 was actually to be used in the place of an iron. The Standard Golf Company's 1909 catalog recommended this club "for
players who prefer a club more laid back" (let's make that "even more laid back than the 3 1/2!").
As is typical with Mills
Clubs, the lie (standard) and head weight (9 oz 14 dr) is stamped on the sole. The 38 3/8" original shaft is stamped "Standard Golf Company" and also has its original leather-wrapped grip.
For more on Mills clubs see TCA2 v1 p338-341.