This is a group of three robots from the great innovators, Yonezawa. They are so-called because of a large wire structure fastened to the back of each of them. It's an unwieldy and, in some eyes, unsightly feature, but it makes identification a cinch. That's handy, because their box names are too vague to be much use. 

You might be forgiven for thinking of the easel support as an afterthought, an add-on that simply stopped the robots from falling over. In fact it's an integral part of a new approach to making the things walk. Why? Because these robots lift their feet off the ground. It took me ages to realise that this is, for the 1950s, very unusual. The flapping feet robots, such as the silver Sparky, only give the illusion of a raised foot, and more modern robots use a broad based foot with projecting spurs (the 'stepover' design). Yonezawa's answer to the instability was the Zimmer frame. It works but, let's be honest, it's not elegant, and it didn't last.

But at least the robots move forward with a graceful stepping action, a pleasant change from the typical robot shuffle, dragging the metalwork behind them.

The basic pressing is the same for all three versions, but litho detailing and some minor structural changes make all the difference. The features that they share are simple square body with a tapering lower section (lithoed to give the impression of legs), flat feet, thin aluminium arms with a quite unusual styling, and a primitive square heads. (The first time I saw those plain arms I thought they were replacements.)

Mechanical Robot

The most common is the wind-up version. It has articulated arms that dangle limply, and a metal cup acting as a spacer. This guy has a coiled antenna running right across the top of his head. The box is a distinctive yellow colour with a robot striding forward.

Battery Operated Robot

 The bare headed remote control version, the Battery Operated Robot, is second in rarity. There's little power required to get this one moving, so he comes equipped with the daintiest little remote control unit (dark green) that holds a single C cell battery. There's just one button for forward motion. He has a half sized coiled antenna, and bent arms linked to springs that give a steady arm movement. The box is stylish jet black with a robot striding forward in a way which the actual toy could never manage. The box carries the Cragstan importer's logo.
 

The scarcest by far, is the remote control version with the dome. The fragility of this dome must account for its added rarity. There's no coiled antenna and the litho work is an attractive bright blue with machinery detailing. It has the same moving arms as the non-dome version. The remote cotrol (blue) unit has two buttons for forward and reverse movement.

Fourth Version?

I have seen photos of a green litho easel back and heard suggestions of a windup version with rivet details. If you can shed more light on them I'd appreciate the information.