Complex sentence: During the 70's he employed a variety of young people to assist and learn how to produce a mural whilst also completing many private commissions-re-creating on a smaller scale some of the success he achieved in the 60's.
Split into simpler sentences: During the 70's he employed a variety of youg people to assist and learn how to produce a mural. During this time he also completed many private commissions-re-creating on a smaller scale some of the success he achieved in the 60's.