The 'chrome-vanadium' wrenches predate the 'Craftsman-Vanadium' wrenches, and are likely from the 30's...
One end probably had an ISN on it, prefixed with a C...
1/2x9/16 should be C-1725B
The other end should say CRAFTSMAN/MADE IN U.S.A.
(One of the few odd cases where craftsman appears twice on the wrench)
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>Craftsman double end adjustable wrench
Diamond liked putting 'Tool Steel' on their double/single adjustables....