Had to check the calendar (nope not April 1st yet). Someone has created a practical joke. There was no such thing as a `walking tank`. The materials technology didn`t exist to make such a thing either support all that weight on spindly legs, let alone the techniques required to keep such a machine in balance while moving. Computers and servo control systems were not invented yet that were up to the formidable engineering challenge.
The `walking tank` is a modern invention of the graphics computer and any that appear in historical photos are a creation of photoshop.