If my construction set is to build complex models that fit into a typical flat, I inevitably need to scale it down. The classic half-inch or even the Merkur ten-millimetre module is just too large.

  Metal construction sets have been around for ages, so long that they're not even retro anymore, but rather pure steampunk. They originated in England at the end of the 19th century, and boys played with them for a whole century before plastics and the fear of manual labour took over in developed countries.