I would agree. I want to try out that original Head and see how it compares to the Donnay I have. I think that will answer everyone's questions right there.
The Donnay Pro One that was a success was the LE. That model was based on the Prince OG OS except tweaked a little to Agassi's specs. So it is logical to say that Agassi loved that Donnay LE and probably went to Head and let them analyze that frame and add their tweaks to it. That ended up being the 260 and his main stick.
So I truly would love to hit with one and see how it feels compared to the Donnay. I would bet that they are probably pretty similar.
I am probably biased, but I think the Donnay LE is one of the bext racquets ever made. I say this after demoing a ton of new modern sticks and growing up playing with Prince graphites.