I think it can be an actually quite common copy. Many copies (as I read) were pressed with the title of a Bob Welch tune, "Good Things (Come To Those Who Wait)", which never came out in the end, because, very close to the releasing date, Bob Weston suggested that the song would be replaced for the "For Your Love" cover which supposedly could mean a hit for the band.
"Good Things (Come To Those Who Wait)" remains officialy unreleased as I understand, even though many vinyl copies of Mystery To Me have that 'original' tracklisting which never went out.
Corrections are welcome.
Song of the moment - Love That Burns