Yeah, the covers do vary, slightly. The onite one is slightly thicker than the hyperion/anker one... Hyperion/QCell use the exact same battery cover, and Anker/Gorilla Gadgets/somethingelseicantremember do too.
I've seen only two brand marks for all the batteries I've opened... around two dozen. I think once the cells are manufactured, they then all go to the same Chinese company that assembles them, and they offer branders pulldowns on a web page to select what they want... they choose the cell part number, the count, whether or not to have shims, and then they can choose the wrapper type then upload an image which gets printed to the wrapper. I find it amusing to imagine that these people can choose how much to screw their customers through a battery order configuration web page.
If you still have that weird battery, I'd like a pic. Never seen or heard of something like that before.