Looking for Lotus Notes 4.6.7a download

Need to upgrade our current Lotus Notes Domino 4.6x servers to L.N.D. R6. IBM recommends updating all servers to version 4.6.7a before migrating to R6., but they don’t offer support for 4.6 anymore! Have searched all over the internet… Can only find an “International” version which does not work. Need the American version. Does anyone out there know where I can find version 4.6.7a (American version)? Thanks.