Thanks for being among the first to attempt this, there are a lot of us out there looking for a quality Leopard theme.
A few tweaks that should be made -
Menubar transparency isn't quite there yet, from what I can tell Leopard's menubar is a smidge more transparent.
Menu corners are slightly rounded in Leopard, also menus are again, a smidge more transparent.
Some kind of Leopard dock skin would also be appreciated.
Anyway, keep up the good work!