Yeah, ‘Heavy Metal Kids’ was on ‘K4’, which is a recording from a Radio Bremen concert (with pretty good quality). The track names there are unofficial, afaik. Some of them could be variations on properly released tracks or those recorded on other bootlegs.

Frankly I myself amn’t a fan of some early Hütter-led experiments, like the incredibly drawn out ‘Ruck Zuck’, which sounds interesting a couple times and is kinda meh after that. This particular track was reinterpreted by the different lineups, and Organisation’s version is groovy, while Neu-Schneider’s one is more hypnotic and at the same time raw in comparison.

It’s very obvious that Kraftwerk were still looking for their proper sound back then. I’m due for a relisten of the first albums, but also am in no hurry to do that, as I never could find anything quite catching the ear. But completely dismissing them like Kraftwerk did is imo unwarranted, it’s a document of the era. Also Dinger was bringing some energy to the music that they couldn’t properly realize until Hütter was gone.