The best glue for all plastic binding is made by Engineered Materials, Inc. They have a special formulation for the Martin and Gibson factories. You can purchase their products in an 8 oz bottle direct from them by calling Paul Polenec at (770) 552-9131. I have been using their EM308B Type II for years and really like it. The Martin formulation is slower drying and I have not really tried it. Gibson's is a newer version of what I use. In any event their info (in addition to Paul above) is:
Engineered Materials, Inc.
P.O. Box 72703
Marietta GA 30007
engma@comcast.net
If you call be sure and tell Paul I recommended them!