Yes, they are the base cards. I would of put "P" or "PS" for the other sets. I have a few of those, but no doubles. I am not interested in those, but keep them in my first set with the original. I am collecting an extra Base set for my Sons. They are 1 and 3. More of a gift when they are much older.
I have P13, P21, P32, P70, P78, PS103, P133, P135, PS136, P146, P157, PS158, P167, SR2014/34 and SR2013/22. I am After Penrith Cards in the Extra Cards / Sub Series. Any of these (Except PS103) can be traded for other Penrith, Cronulla or Brisbane Team cards in the "P" or "PS" sets.