I'd consider getting a non-US x121e if I knew that I could successfully swap out the keyboard for a (new) US-version keyboard from an x120e. My guess is that there are several reasons it might not work. But, is anyone with an actual x121e willing to send me precise external measurements of the keyboard?

Thanks.

The x121e has it's own part number, so Is likely that some minor details could block the swap.

BTW, if the old and new keyboards are made by the same OEM (there are only two, guess Chycony or NMB) very likely you will be able to swap the single keycaps.

You can also take a look to 4keyboards that sells keyboard some stickers, they are really well made and durable, they are really thin and the finish is really close to the one of the real keycaps. They are also available in dual language configuration.