Find an upper case with original keyboard, not Chinese one.

Sadly you are between a rock and a hard place! There is no markings on the keyboard that proves its an original part, keep in mind Apple has long purged its self of the parts for this older MacBook Air system. So you would need to put on your hike boots traveling to each authorized Apple repair shop to see what they have on the shelf that still has dust on it. I doubt you’ll find a real one as they too would have long since sold their spares and most don’t keep many spares anyways.

So where does that leave us? The only way I know of to get a real Apple keyboard is to buy a used part from a company that repurposes used systems for parts. One of the largest is in the UK, which is where I get many of my parts. Here’s a listing on what they carry for uppercase parts for your system: 11” MacBook Air Mid 2011