RE: Applying Monokote to Monokote
I would try to peal that decal off and with your iron seal the covering to the ribs, sheeting front and back trim the hole back to the ribs and sheeting that you just sealed the covering to.
then clean the area good I use rubbing alcohol cut a patch to cover the hole and seal it down all around keeping all the wrinkles out that you can then carefully shrink it smooth.
Good luck.