Yeah the Pro One was never 18/19, even the actual one Agassi used. I owned the consumer Yellow/Blue Pro One that Donnay tried to get him to use which subsequently he didn't like and went back to using all black painted Prince Original Graphite OS racquets with the Donnay stencil on the strings. My educated guess would be that Donnay had already commited to and manufactured a large stock of them to sell. I specifically remember reading articles in Tennis Magazine that said Donnay went back and studied the Prince Graphite some more and came up with a custom Yellow/Blue Pro One for him. That Pro One later became the Orange-Pink/Gray Pro One Limited Edition (which I also own) model that was sold. Though I'm sure Andre's Pro One LE still had some more customization specific to his needs, but the consumer Pro One LE was still made from the same mold. Since the Prince Graphite was 16/19, it makes no sense to have made the Pro One 18/19. Also, the batch that Tennis Warehouse has now has been stated to be made to Agassi's specifications:
"With both positive feedback from our in-house hitting and our Talk Tennis faithfuls, production of prototype racquets began. Our "made for Agassi" racquets were shipped to the manufacturer to ensure everything was up to spec and that the colors were replicated exactly."
So again, there was never a 18/19 string patterned Pro One. Just look at this picture of Agassi from the '91 French Open and you can clearly that it has a 16/19 string pattern:
Again I'm going with what has been stated in an old thread that discussed Agassi's racquets and I honestly believe that he has used the same Head Radical since he signed with them back in '93. It's simply that he had to have paint jobs on his original Radical Trisys 260 to match whatever model racquet was out in each particular year he was active. If there's another thing you can look at is the shoulders of the racquet he uses and you can see how it contours inside whereas the Pro One is flat.
Here's a pic from what appears to be the 2006 US Open, his last:
You can see the shoulders and how they contour inside where they meet up with the throat. Aside from the picture distortion arguement, I've looked at many pictures and the shape of the racquet he uses looks very much like the Radical Trisys 260. Not trying to beat a dead horse here and originally I was just peeved to find out shadyness of paint jobs, but as it has been stated in a previous thread (and quoted from an "unamed Head rep") that Agassi's racquets were indeed manufactured by Head and that he most likely stuck with the same racquet (minor tweaks here and there possibly) that they originally designed for him.