Yes I was collecting comics in the '70s. It was very difficult getting hold of back copies, especially living outside the USA. (I am in Australia). You had to mail away to dealers to get their price lists, then send your order with a bank check. It took 2 weeks at least for the turnaround. (Amazing that the post was so good back then - I am still waiting for a shipment that was sent by USPS on 20 December, which they have lost track of and according to them is still in NJ).
Anyway because of the tyranny of distance the dealers knew they could get away with sending poor quality books - so for example I paid for a AF 15 in VG or better and got this:
If it had been VG or better I could retire now...