Are you sure it is PPC Mac?
MOS won't work on Intel MiniMacs!
Obviously I can't speak for the man but the odds are it is a PPC MacMini - there were some 1.5ghz intel models released but they almost immediately jumped up to 1.66 and beyond.
Not saying it isn't, and by "some" of course even for Apple means several tens of thousands, just that the odds on would be that it's a PowerPC based one.
