many types of course. Generally speaking do the materials used in pc's from the 80s fall into a single category? Everything is injected into a mold for sure, from largish cases to tiny keytops. Would all this qualify as polystyrene? Whatever the case, what's a good solvent (not necessarily glue) that's useful for repairing big cracks or splits, to tiny hairline cracks. I say solvent, and some glues can fall into this category, because it makes more sense to reinforce the materials from behind to effect a strong bond, and for cosmetic sake meld the item from the front, to obscure the defect itself. Many surfaces are anything but smooth. Has anyone tried, given they were successful in melding the surface, in reproducing the look of the surface surrounding it? Smooth surfaces can be melded then touched up lightly w/ultra fine emery cloth and some sort of lubricant I would guess. But the rough textures are a different story.