I have a York compressor with a tag similar to Richard's. The tag's date code 047K is similar, which would be April 1967. Mannel (p. 7-31) says the trailing letter; K in this case, "had no date significance."
Since I have a car that was built on 11/30/1966, I'd be looking for a Nov 66 or Oct 66 date-coded tag too.
May be just a coincidence: 047 is on the tag of the three York compressors discussed here.