Arthur Stone retired in 1937 and sold his shop to Henry Heywood.  
The Stone Sterling Shop mark was used c. 1937-1938.
The business was quickly renamed Stone Associates.  Usage of the Arthur Stone
mark was resumed with the addition of a lower case H in a shield.  This mark was
used 1938-1957.
Arthur J. Stone shop mark, used c. 1906-1937.
Stone's earliest mark was a simple chasing hammer and was used c. 1901.  
Another mark, a single S with a hammer through it, was used beginning around 1902.
Because of high demand for his work, Stone began taking on
assistants in 1906.  Stone wanted each of his assistants to sign
their own work, so each craftsman's surname initial was added
along with the Stone shop mark, either next to the Sterling mark
for flatware or below the Sterling mark for holloware.

We have included a table of assistants' marks further down on this page.
In some cases it can be determined who made an object and during what
time period.  In other cases, because different assistants shared the same
initials and specialties, it is impossible to ascribe a particular mark to a
particular person.
Heywood's sons continued to run the shop until 1957 when it went was closed.  Ernest W. Lehtonen
acquired the mark which he used on flatware, changing the lower case H in the shield to a capital L.
Arthur Stone Workshop - Table of Assistants
Speciality
Name
Mark
Date
1906-1907
1912-1914
1912-1937
1912-1937
1909-1937
1909-1919
1909-1912
1907-1911
1906-1910
1914-1916
1931-1937
1924-1937
1922-1932
1921-1927
1920-1937
1915-1932
B
B
H
C
L
T
B
O
B
P
c
C
U
G
E
P
Herman W. Glendenning
George C. Erickson
Edward Billings
Magnus Carlberg
Earle H. Underwood
Walter W. Pfeiffer
Clinton B. Ogilvie
David Carlson
Sylvanus E. Lamphrey
Herbert A. Taylor
William Blair
John H. Petty
Benjamin H. Harrison
Charles W. Brown
Alfred Wickstrom
Arthur L. Hartwell
Flatware
Holloware
Flatware
Holloware
Flatware / Chaser
Holloware / Flatware
Flatware
Holloware
Holloware
Holloware
Holloware
Finisher
Holloware
Holloware
Flatware
Flatware
Holloware
Chaser / Designer
After having worked decades for large silver companies such as Dixon & Sons, the Wm. B. Durgin Co.,
and the Frank W. Smith Silver Co., Arthur J. Stone established his own workshop in 1901.  
.
.
.
Herbert A. Taylor
1908-1937
Herman Glendenning
1920-1937
George P. Blanchard
1906-1910
or
Charles W. Brown
1912-1937
George P. Blanchard
1908-1909
1908-1937
H
W
Edward L. Caron