Identify keyboard localization

Solution 1:

It very closely resembles French keyboard localization as per Apple support document, How to identify keyboard localizations.

The keyboard has French localization. The keys have been manually swapped to change the layout.

However, the layout on your keyboard is QWERTY while Apple support document illustrates AZERTY layout.

As mentioned by Tetsujin:

It looks like some kind of hybrid; it's a French layout but with what looks like a standard UK or International English qwerty inset. The letters match qwerty, including where the azerty layout has to 'move' keys elsewhere

In order to have output match the keys, you could create a custom layout with Ukelele or Karabiner.