This is the 2nd Purple label pressing from 1978; read the details below at #2, as they apply to the label of this version.
Variations for the purple label:
#1-Purple label with large Capitol logo, has the Capitol script-font logo in the perimeter print: 1977.
#2-Purple label with large Capitol logo, has a softer purple background with no Capitol logo in the perimeter print. The perimeter print states “Manufactured in Canada By Capitol Records”: 1978 [this submission, see close-up images above].
#3-Purple label similar to #2, but has “Manufactured in Canada UNDER LICENSE by Capitol Records-EMI….” in perimeter text. 1980. The 1980 variation, including photos, can be found here.
On spine of this submission: MG logo (Modern Graphics) with “Litho in Canada” [see images].
Also issued on the Black rainbow/colorband label in 1983, those have “Manufactured and Distributed in Canada Under License by Capitol Records-EMI Of Canada Limited” included within the rim print on labels.