It’s always interesting to see logos from decades ago, you can see how design has progressed since and what factors have stood the test of time. Looking at these it’s clear the are all from the 60’s and 70’s, their usage of bold curved designs indicate this era well.
Looking at the PG design this has a few characteristics of logo design from this era, most notably the three lines effect. The same can be seen again in ‘The Georgian Group’ and ‘Gerard Martin’ logos. Obviously this was one of the design styles of the time that certainly hasn’t passed the test of time.
Having sheets of old logos such as this is always useful, if we can see what design factors can still be current decades on then we can learn how to create logos that will last for generations.