I’ve found a copy. The cover is just the same as the 1st edition. There is a short new preface to the second edition which reads:
“A few changes have been made – particularly in the Occultation section. Since 1972 Mr. Ringsdore has, unhappily, been compelled to retire as Section Secretary because of ill-health. In his place, we welcome Mr. Geoffrey Buss.”
The only change I can see in the 1974 edition is there is an additional page on occultations, see attachment.