Glen, I think what you are seeing is the overhang that I allowed. I first draw a line around the template and then another line about 1/4" outside of that to allow for overhang to be trimmed off after closing the box and then I route the binding/purfling channels. Please correct me if I'm misunderstanding you.
The way that I do this is to put a washer against the edge of the template, put a pencil on the inside edge of the washer and just roll it around the template.
David L
