If you use super glue instead of the hot glue, the paper will become more stiff. Then when dry you take light grade sand paper around the edge and it will wear away enough so that the seam will vanish.
I used this trick for minor repairs in plastic items. For example there was a broken airsoft gun that I was able to obtain for a low price. I was able to make the necessary repairs with paper, super glue, and scrap plastic.