Dave, one of the reasons we encourage members to list the equipment and experience they have is so that we can tailor the advice we give. It seems I remember Harry or James saying once before that most routers sold down under are plunges? If that's the case then follow James advice. You can make a template to follow. If you use a pattern bit to cut the recess then you can make the template the same size as the vise base.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.