Repair with Gorilla Glue  

I just cleaned a large bubble lamp with TSP and a soft brush and am very pleased with the result. I then repaired a small tear along the side of a rib by VERY CAREFULLY applying wet gorilla glue with a stylus only in the tear. After the glue bubbled up, as it always does as it sets, I used a straight pin to carefully texture the surface of the glue to match the texture of the lamp, then let it dry. The glue came out exactly the "yellowed" color of the lampshade and is almost impossible to detect. Since the repair is right along a rib, it does not even show when the light is on.
Hope this helps someone else.
Cathy