Box says MD512LL/a on the box but "model 4158" on the device. It was an open box so I'm checking to make sure the store verified everything and since I can't find anything about the latter number listed.
I think you mean model 1458, not 4158 as you stated.
This article identifies that model:
Googling MD512LL/A seems to point to the same model.
Yes. Not reversing the numbers would probably help. Is there really anything to do besides reset to factory standards and make sure nothing is on it?
You are referring to two different numbers that mean two different things. My telephone number is different from my Social Security number, yet both refer to me.
You can do Settings > General > Reset > Erase all content and settings just to make sure.
Then you would start with a factory fresh iPad.
Retrieving data ...