Model steam engine AKW R200 by Wilesco was made only about 10 years from the late 1950s until the late 1960s and resembles a miniature Atom Power Plant, 'Atomkraftwerk' in German.
The 1960s were characterized by a kind of 'euphoria' and nuclear power was seen as the 'energy of the future'. This model nuclear reactor station steam engine is a testimony from those times when environment, ecology, security and future issues were not on everyone’s mind. However, sales were low due to the fact that most people were also afraid of anything that had to do with "Atomic Energy" (dangeorous!), and as it was associated with the Atomic Bomb and the Cold War. The engines came with a booklet explaining how Atomic Plants produced electricity.
This Wilesco model is particularly collectible due to its nuclear character and quality finish, like most Wilesco engines.
It's pretty rare to find nowadays, because there were only a few manufactured at the time and... you know... in the hands of kids. But now and then one shows up on eBay so if you check regularly you might pick one up one day.
The R200 is based on the D10 platform, has a 16mm. stroke, 9mm. diameter and 70mm. flywheel. The boiler is heated by electricity, 220v in Europe, 110v export models, 250watt.
What's it worth? Take a look at this Wilesco R200 price guide: sold listings for a value indication.