Will GBbooks show small marks or cosmetic differences?

They can, especially when vintage, repurposed, or manually assembled elements are involved. This should not be surprising, because the project does not position GBbooks as sterile industrial replicas. They are physical objects that sit at the intersection of handmade work, retro hardware culture, customization, and small-scale production. That means minor differences in finish, light signs of age, small surface marks, or other cosmetic variations may occur from one unit to another. Those differences are not automatically flaws. Often they are simply the visible consequence of working with real materials instead of pretending everything came from a frictionless factory pipeline. If absolute visual uniformity is critical, that expectation should be discussed upfront.