Sounds very plausible PhilMH. If I'd had to guess I'd have gone for somewhere around the late 1980s/early 1990s (assuming that this was the first CD version) as the original LP was a big seller back in 1979 (#7 on the BB "Pop" LPs Chart) and would have been a prime candidate for a reissue once the CD format had got well established.
Seems to be early 1990, Roger, based on it first appearing in the Spring 1990 Schwann Spectrum catalogue, but I don't have anything that would give a more precise date.
Another entry where I'm not sure about the release date.
Discogs have "Unknown", Amazon.co.uk have something on sale that looks identical that they say was released in 2013, and yet I must have had this CD for over 10 years.
The Cat# doesn't give away any clues either, as it uses the same number as the original 1979 US LP.
The insert is one of those "fold-out" affairs that has six "pages" (three on each side), all of which are in the images I've added for this.