This is one of the most amazing pieces of quilted art I have ever seen! You are truly an artist to start with and your fabric medium is very well done. Definitely seek the advice of a quilt museum such as the one at the University of Nebraska. Consider contacting Linda Taylor, a well known longarm quilter and instructor for advise. Your work of art deserves the best advise to enhance it and protect its integrity. Whatever type of quilting you are advised to do will enhance the project rather than compete with the artistry. Please be sure to let us all know what you decide to do.