how to make a linkable text box after deleting the default one in the layout

I mistakenly deleted the default text box on an ibooks layout that I have worked on for 6 months. The design is image intensive. Now, I want to add linkable text boxes, but I can't add a text box that is linkable to other text boxes. I can only make stand-alone text boxes. Does anyone know how I can make a linkable text box after I have deleted the default one in the template? Please help me save 6 months of my work in the process if you can!

OS10.9.3

iBooks Author 2.1.3

Warm regards,

Jamil