North American Salisbury axles

The stamped numbers under the nose could well be a date code, but we would need more observations to build a consensus on that supposition.
The axle from 681114 (Apr '53) has C53 559 there which could be the 559th axle built in March 1953, and the one in my April 1950 Mark V has A 0 1786E which I suppose could be Jan 1950 if somebody forgot to stamp the 5.
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