I remember watching this film in 1981, when I was 7. It was absolutely brilliant! I found the DVD just a couple of months ago. I was nearly jumping up and down with glee!! I bought it and showed it to my kids. They loved it too. They asked what words the seahorse was singing (I didn't tell them, though, because I don't think telling the words 'gay' and 'ecstasy' to 6 year old kids is very good parenting). The songs are brilliant. I still remember them all. I'll still remember them when I'm 60! There, or near abouts. Tommy Pender is (was) such a brilliant actor. It's a pity he gave it up.
If you find the film, BUY IT! You'll love it!