To calculate and place the holes in the design i would use and alpha image of the g and extract the innder shape, this gave me a perfect vector of the shape. I would then add another master grid tothe masterpage, this ensured consistant placement throguht the book. I would also place the images on a seperate layer and lock it down to stop any accidental movement. using the opacity i was easily able to tell what the book pages would look like.
Again printing out a few low Q test runs confirmed what i knew.