The Dart VL-852 is as mysterious as it is stylish. It was sold by wonderfully named Dutch company Superlectron, which also produced a Pong system, some computer monitors and other calculators (mostly under the Superlectron brand).
Little appears to be known about this device and the company that sold it - if we want to know more, we'll have to do some electronic archaeology. Two screws are hidden in the battery compartment, the removal of which permits us to open up the device. This is what we see:
Bingo. There's a transformer made by Taiwan-based Dee Van, but let's have a closer look at that chip to the right - the A4130 made by Rockwell. This calculator-on-a-chip is stamped '4B', meaning it was made in the second quarter of 1974. We have a date!
The calculator is 121mm high by 71mm wide, and it tapers from 30 to 18mm in thickness. It takes a 9 volt block battery.
It turns on by a sliding button on the top right of the button pad. It has a Vacuum Fluorescent Display (VFD), as type of display still used today in places that are subjected to abuse. You'll find them in cars, microwave ovens, and some handheld video games from the seventies.
Interestingly, this is a fairly complicated device and it has two modes, allowing for various button combinations, enabling the user to type in more complex calculations than this type of device usually does. The back of the calculator has a cheat sheet with instructions: