On ebay, I found this computer, which is either still not sold for almost a year or re-offered.
It was also mentioned in this thread, they didn’t know what is is (although the label and parts suggest that this is a language lab computer)
The real vintage 70s language labs had no computers but a big panel for the teacher and some few buttons and headset for every student. On most images on Google you mainly find the teacher’s panel, with the German term Sprachlabor you find some better ones.
Very interesting is this rather small but thick panel box for the C64
Some more images including rear
While the form factor somewhat reminds of the VIC 20 and the PET, I don’t think that this is PET-related, despite the name. Mind that the keyboard layout is quite different and that the characters do not look like Commodore 8-bit characters at all. (The characters remind me more of things Sharp was doing at the time. Also, mind the badge “Made in Japan”. – Didn’t the design of the VIC 20 draw from a Japanese computer that featured yellow function keys? I faintly remember reading something to this extent.) Even if vacuum formed, the case couldn’t have been inexpensive. (One of the images show a crack on the rear side, so it must be some sort of plastic. The monitor housing seems to be made of metal, though.) – Quite some effort went into this.
Sadly we don’t get a look at the PCB.