Hmm ... does perl -V:libperl report 'libperl514.a' ? On my x64 ActivePerl 5.10 (build 1005) where I actually use ExtUtils::FakeConfig, I find that Config_m.pm sets libperl='perl510.dll'
I don't think that should be necessary if you have libperl514.a ... but, anyway, try setting libperl='perl514.dll' in your Config_m.pm and then check that perl -V:libperl reports 'perl514.dll'
Cheers, Rob
Update: As I tihnk about it a bit more, I think a better thing to do is to re-create libperl514.a using gendef and dlltool (as detailed earlier).