The first and only LP by Düsseldorf’s German Oak isn’t the absolute rarest krautrock record in existence, but it’s up there. Its backstory ticks all the hyperobscurity collector cliché boxes: released during a burgeoning period for strange, indulgent music from the Fatherland (1972), at the behest of an overbearing manager as clueless about the market as his charges. Pressed privately in tiny numbers, most copies remained unsold, until leaking onto the collector market in the 1980s.

Until now, anyone who’d heard (of) its nightmarish proto-industrial space jams, seen its extraordinary black metal demotape-alike sleeve art, and wanted to cradle their own copy could either pay hundreds of quid for an original or much less for a snide reissue. That’s changed thanks to American archive label Now-Again – specifically Now-Again Reserve, their sublabel for unfeasible rarities – who’ve come through with a hulking remastered triple-disc package, extensive bonus material and an illuminating interview with German Oak guitarist Wolfgang Czaika.

Anyone previously familiar with German Oak will notice a few changes. Firstly, it’s not called that any more, it’s titled Down In The Bunker, a reference to the subterranean second world war-era bolthole in which the album was recorded. The song titles have changed, too. German Oak never bothered with such things, so their manager and sometime organist Manfred Uhr chose them. The group’s Malcolm McLaren or John Sinclair figure, if evidently without the marketing nous, Uhr pushed the ‘bunker’ theme to the hilt: the LP’s brief intro and outro pieces, which bookend two epic workouts, were titled ‘Airalert’ and ‘1945 – Out Of The Ashes’ (now ‘Screaming Skeletons’ and ‘Nothing’). This is already chancing your arm in Germany, so the unreleased cuts Uhr dug up for a quasi-bootleg early 90s CD issue – including songs he’d named ‘Swastika Rising’ and samples of Hitler speeches – shone a light on the band they’d done pretty much nothing to encourage. Which is why they’ve retitled everything and excised the dodgy samples.

That said, German Oak’s music is often noxious and creepy enough to feel like an antecedent of some of the underground’s notable fash-flirters: Death In June, Current 93 and Coil seem to be born in the 19-minute ‘Missile Song’, which cycles through clanging metallic percussion, ultra-sparse crypto-jazz drumming, a bass sound beamed in from a deep bath next door, outbreaks of haphazard haunted house onomatopoeia by unnamed instruments. It’s a bit ‘Set The Controls For The Heart Of The Sun’, early Faust, Sun Ra even, but sonically stunning for three rudderless rock trippers who basically just tossed this onto tape with no real thought about what might become of it.

‘Belle’s Song’, at 16-and-a-half minutes, is the original LP’s other main event, and the railroad boogie rhythm at its core cleaves closer to rock convention – the more eccentric end of it though, certainly. Groundhogs fans might well dig on this fuzz and wah and chug, for example, even/especially when Czaika bends his guitar off the map in sick psych style and Ulli Kallweit’s drumming breaks for the border with buoyant freeness in the closing moments.

The extended and alternate takes which fill discs two and three are divertingly gnarly, but don’t indicate much obvious potential for German Oak to have become pored over by obsessive live bootleg collectors, Grateful Dead or Velvet Underground style. The original edits of ‘Belle’s Song’ and ‘Missile Song’ run to 26 and 34 minutes respectively – I’m reviewing the CD version here and am curious as to how the latter fits onto one side of vinyl – and become slightly more and slightly less weird, also respectively, in doing so. ‘Missile’ is gussied up with lengthy periods of hard rock scorch which is perfectly decent in itself, but a distraction from the eldritch immersion created by the edit; ‘Belle’ fleshes out the rubbery reverbed guitar sound that Czaika switches to having departed the boogie rhythm.

The remaining seven songs were recorded in Czaika’s house, and find German Oak getting riffier and more Hendrixian: things like ‘The Bear Song’ (retitled from ‘The Third Reich’ – I call this an example of the great German humour, except not sarcastically) and ‘Python Vs Tiger’ burble along with a pleasingly lumpen tone and the suspicion that a majority of LSD-using experimental rock bands of the era had rehearsals that sounded much like this. Although this release is the very first to have the full collaborative approval of the German Oak members, even this comes with a caveat: Czaika dismisses their entire output in the interview as “musical scrap and waste … sins of our youth”. The ever-swelling reissue market teems with variations on this, of course: one-time, one-shot lost crazies tracked down only to express (sincere or otherwise) astonishment that anyone might now care about their throwaway hobby band. Not many of them are dug up with as much tender care as Now-Again offer, and few of them sound as unearthly and ahead of their time as German Oak.