[skc444]

I was recently in the same situation as you. I bought a 1972 topps football wax pack graded by PSA but it didnt state what series it was. I was able to identify the top card as a Mike Mccoy Pro Action card due to the "white dots" on the right which are actually the crowd in the card's background. Once I received the pack, I could see through the back of the pack and identified the back card as Buck Buchanan. I checked to online and saw that the Mike Mccoy and the Buchanan both belong to series 2. Thus Im pretty sure my pack is a series 2. Might be tougher if your pack is a darker color. Hope that helps with your situation.