April 25, 2012, 12:50
Lindell V. RiddleKEYSTONE-HAMILTON MAINLINER, A, 11, 14 AND 17 DATABASE EXAMPLES YEAR-BY-YEAR
_________________________________________________
KEYSTONE-HAMILTON MAINLINER, A, 11, 14 AND 17 DATABASE EXAMPLES YEAR-BY-YEAR
We begin with numbers for the Keystone-Hamilton "Mainliner" Case which was introduced in 1937 and then, since they all use the same numbering system, proceed to the Case A introduction in July of 1940 followed the same year by the Case 11 and later the short-lived Case 14 in 1949 up through the Keystone-Hamilton "Railroad 17" along with the last "A" cases including an exceptionally rare 14K Gold Case A produced in the mid-1950s.
Start out by looking up your Hamilton movement on the Hamilton Serial Number Listings Preserved by John F. Gelson then check the Keystone case numbers and years of production on this list for the one that comes closest to yours. If your movement and case are an original combination the years should then be a reasonably close match.
Here are some representative Mainliner Case, Case A and Case 11 approximations from our assembled data...
1937 - 1070000
1938 - 1071000
1939 - 1175000
NOTE: The earliest Hamilton 950 Elinvar Mainliner Cases had "Hamilton Railroad Model" markings, by 1940 they carried the same "Hamilton Watch Co." markings as we find on Case A and Case 11 Examples. (See second image below.)
1940 - 1210000
------- During 1940 they began using a "K-Prefix" -------
1941 - K1310000
1942 - K1360000
------- During 1943 numbering system changed to "K0" and shorter overall numbers -------
NOTE: Some cases numbered without the "K" prefix but beginning with "13" have been found, these are apparently part of this particular numbering transition period.
1943 - K030000
1944 - K039000
1945 - K041000
1946 - K090000
1947 - K170000
1948 - K200000
------- No High-Shoulders after about K220000 in 1948 --------
1949 - K260000
1950 - K315000
The Case 11 disappeared entirely around this point, last shown in 1951 advertising but the Case A continued to be offered through 1956 in the Hamilton Catalog. (The Case A was offered in Solid 14K Gold and at this point only two of those are documented as surviving. For a short time in the mid-1950s the Keystone-Hamilton "Railroad 17" case was produced using this same numbering system. Then the later Case 17 produced by Star using Keystone dies employed Star numbering.)
Here are some examples of Keystone-Hamilton cases for those years...
1951 - K350000
1952 - K365000
1953 - K380000
1954 - K400000
1955 - K410000
1956 - K415000
This is a list through the years based upon representative boxed-set examples from our assembled data, subject to revision.
Hope this basic information is of help. (Entire topic © 2002-2020 IHC185 All rights Reserved)
Stay tuned!

Please send comments and suggestions to ihc185@roadrunner.com
_________________________________________________