You might start by contacting the publisher. They will know who owns what rights in the drawings, and may even know if they are available for license.
In a normal delivery, Momcat will chew it. If she needs help, tie off 1 inch from the umbilicus, and 1 inch from the point of attachment in the Momcat , and cut between the ties.
If she hasn't expelled it a half-hour, see if Momcat will let you give her some belly rubs to stimulate the action.