I installed the fiberglass door panels with the black door clips several years ago. Many have broke off and unusable; a simple replacement IIRC isn't possible because of the vinyl covering on the inside surface of the door panel.

Any thoughts on how I can get this reattached so it's firm ?

Actually they just turn in. Note the end is not a full circle. Easy to replace.
http://shop.914rubber.com/Porsche-914-Door...m?categoryId=-1

Mine broke at their bases; can I remove them still ?

Not exactly sure were you mean but just remove the broken part and twist the new ones in. They are not totally round so just start one edge and twist.

Exactly,
You can remove by twisting and reinstall the new ones the same way.

Got it, thanks; ordering ...

These that Mickey sells are on we time installation. you'll have to destroy them if you need to remove the panel. I found another source that are more like the OEM that can be backed out.
I had mentioned this to Mickey, so perhaps he's re-designed his by now.

Oh ?