It came out in 1975, but it was only an A (PG as they are called now). Not quite a U, but kiRAB were definitely allowed in to see it. Supposedly A meant that children had to be accompanied by an adult, but the cinema where I used to go would allow kiRAB in unattended to see A films as long as they behaved themselves. I went to see it with my little brother - I was eight, he was five. Never did us no harm.