As you can see, the keyboard has a serial number and the brand only on the back:
￼ Adesso is a recognized brand from back in the day and a competitor to Matias from what I recall.
They made lower cost alternatives to the Apple keyboards. The still make keyboards, but their latest offerings are horrible. The FCC ID and it appears to have been manufactured by Wentek Technology, Inc. Although I cannot confirm, Wentek is also known as Ortek, Inc. Apparently, they made a bunch of similar looking keyboards for other brands with ALPS switches under the brands Precision Devices, Inc. and Micro Warehouse Power User.
I can’t tell if they are true ALPS or some clone. It feels like the black ALPS on my Dell Black Bigfoot, but smoother with less tactility, although you can hear a subtle ping occasionally. I suspect this is what’s meant by linear feel. The keycaps fit perfectly on my Dell as well.
The question remains, are these true ALPS switches or am I getting too excited? The switch in the photo doesn't have the characteristic ALPS logo on it. I have other genuine ALPS switches that don't have the logo on them either. Looking at the images in the wiki for the SKCL green, none of them look like this one, but the tale tell sign is the tiny four small tabs. Sigh, well I can't be that lucky. Does anyone know who makes these switches?