In Nasser on the Way Part 2 he videotapes himself during a Flex photoshoot. He makes a few different poses, wears sunglasses, takes them off, etc. for Chris Lund to take pictures...and then they move on to taking a picture lifting weights - specifically the overhead dumbell press. You can tell the weights are real because even has he warms up there are two people picking him the dumbell and passing it to him. Finally for the set with 200 the two guys STRUGGLE to pick it up to Nasser's lower-head level, where he takes the weight and starts doing his reps from the bottom - gets five reps and you can tell by Nasser's shaking and speed of the reps that it's the real thing. During the five reps Chris Lund is taking as many pictures as he can.
Conclusion = Flex weights during Nasser's time were REAL.
