The theme is a derivative of the moin default theme, so will have to be GPLed as well.
Radomir’s main website seems to have been replaced with something non-Python related. I’ll ping him. Perhaps he can make the theme available on his Github account at deshipu (Radomir Dopieralski) · GitHub
Alternatively, I could upload the actual version used by wiki.python.org to my Github account and we could take it from there. I’m not sure whether this was tweaked compared to Radomir’s original version at some point.