Some changes have happened since the 70s.
We'll start with Grissom Island a manmade island with disguised oil derricks on it.
Over time there have been a different number of derricks on it and in different spots, with the same general disguise on them.
Next up the small craft harbor that wasn't there in the 70s, you can also see that in the 70s aerial the little bump out was just dirt, no grass and sidewalks.