As a vintage computer enthusiast, I found myself with many older PCs that had lost their shop sticker.  Maybe the sticker was damaged or faded to the point where it no longer added to the aesthetics of the case.  Maybe it was a "new" vintage build with a NOS case that never had a sticker to begin with.  Sure, you could put a generic "Intel Inside" sticker in that little one-inch-square recess and it would look pretty decent.  I know, I've done it more than a few times.

Y2K stickers on glossy white vinyl (these are reproductions, not vintage stock).

These will ship via stamped envelope - and I will make sure that the sticker is protected inside.