Dale,
I didn't get any advice that I already hadn't tried. In the past I've warmed the decal up with a hair dryer and then used Elmers Glue. Elmers dries clear and is water soluble, so it is forgiving to work with. Any that oozes out from under the decal can be wiped away with a Q-tip dipped in warm water. You may then hold the curled end in place with your finger or wrap a soft handkerchief around it to keep it in place until it dries. It also will not harm the inks on the decal. I've used this on rim decals also. However, some decals are just too curled or too brittle to even soften up and lay in place and that is the problem I was hoping to find an answer to.
Tony Brown
Reading, PA