Chic - regarding your comment about Levrone, I understand the point you are trying to make, but I really doubt he would get any decent gains if he spent 6 months training naturally. First of all, I think his motivation training naturally would be very low, and secondly, I think his body would respond poorly.
Now on the other in, if you added some test, a bit of GH and bit of Winstrol, then I think, yes, he would blow up pretty big, and would make amazingly quick gains.
Do you honestly know any former pros, who have made a decentr come-back naturally?