Try this:
hxxp://www.raredolly.com/gallery/view.asp?gallery=60s%20Photos&pic=Essential%201.jpgBottom line is, I don't think you can make the comparison you want to because of the changes in her act, and her wardrobe. It's going to be tough to find full body concert photos fom an era when she was more of a studio recording star. In none of the photos you've posted is there a convincing angle that would show precisely how large her bust was at that given time--the clothes are either too loose, or the angle is inconclusive.
Additionally, assuming that as an 18-19-20 year old she was a "mere" D-cup, from a purely physical standpoint, women develop at different rates. I know many who "blossom" early and then grow into their bodies, and others who suddenly sprout curves in their twenties. Then again, others stay lithe until their metabolisms slow down in their thrities, or even forties. Look at Michelle Angelo, who was a D in her modeling career, then turned into an I-cup by the time she was nearing 50.
How are you going to reconcile all of that with your idle speculation that she had some help, based upon a few photos?
Historically, Dolly's weight *has* fluctuated, and her breasts DID appear larger during those times. I think that, unless you've got some pretty compelling evidence, this is one of those arguments that you're doomed to fight without proving anything. But we can agree to disagree.