If its "outrageously small but can still take you and a goose to market", Citroën have a tiny little electric vehicle, the Ami, today.
If its "something simple enough that a farmer can weld the panels themselves", I fear those days are long gone, in the same way that the OG Land Rover Defender is no longer a car you can wrench on. The spiritual heir of such cars is probably a toyota hilux(?). Modern safety standards and the presence of complex electronics beneath every surface, to say nothing of the more complex sheet metal shapes, probably stop that idea in its tracks.
