Koster, you can check out the link below. Go to the articles section and read 'All About Jigs'.
Beyond the drawing, or buying a public jig, I don't think anyone is going to give you the dimensions of their call. That is something you have to figure out on your own (just like all the rest of us have).
One dimension that most (not all) duck calls are made on today is the bore of the barrel. Most use a 5/8" bore (15.87mm).
BTW, the 3rd party hosting icon is a result of the photo hosting company now demanding large sums of money from the original poster (myself included) to have the pictures shown again.