I've soldered like for like before too, but never a newer one, the size and position of the pins would have to match, thats all. The adaptor by Madsonline and called "Generation Gap" Allows older "Big Plug" adaptors to be used by the newer 'books. Never seen one that went the other way.
PB G4 15" 1.2ghz - Pismo G3 400 mhz - iBook G3 500 "Jukebox"
"SawSmurf" G4 500 - Quicksilver G4 Dual 1ghz modding...