the body is okay, maybe bring in some more datails in the edges, best for rendering details. and most of the time these things consist of two sides, its a manufacturing issue. so a thin line thats separetes the top from the bottom, bump mapping should be enough. its missing some details in generell, i would ay provide more edges and it could be much better. the earphone looks a bit meltet, or made of rubber, it needs more straightness or should look more made by robots, even when it is an old phone. for myself i love to bring in some chrome elements, thin details at some points. can look more vintage then.