Where to find Twenty Ten theme old versions — 1.0 or 1.1?

Where can I download older versions of the Twenty Ten theme?

(I’m working with a website where someone made a copy of an early version of Twenty Ten and modified it. I’d like to find the matching old version so I can compare the theme with the version of Twenty Ten it came from, then re-implement the changes as a child theme so maintenance is easier.)

Thanks!