George Young went on to produce a number of albums for another Australian band, AC/DC, which was founded by his brothers Malcolm and Angus, and (it sez here) played bass in AC/DC for a short while. An older brother had a band called The Grapefruit.
Speaking of AC/DC, check out Bon Scott here with his band The Valentines.
http://www.youtube.com/watch?v=BQ-45XG7n4k