A fusion crust is the most characteristic feature of a meteorite. If it has “worn off” from abrasion and ablation, then it is all but impossible to identify the rock as a meteorite just “by looking.”
Think of it this way: If she’s wearing a pretty dress and playing a grand piano on a stage with a symphony orchestra behind her, then she’s probably a concert pianist. If she’s jogging down the beach with her dog, then she might be a concert pianist, but probably not. How can you tell?
These rocks do not have fusion crusts because they are not meteorites, not because the fusion crust “wore off.”