The Revolutionaries Top Ranking Dub Volume One (Duke Reid, 1978) ... The typeface used isn't especially 'metal' but the red-eyed ghoul in WWII Nazi helmet imagery sure is. Who knew Eddie liked dub? Decent enough album but it only gets top ranking on this list due to the cover art.
Phil Pratt Star Wars Dub (Burning Sounds, 1978) ... Darth Vader and lightning bolts are both hella metal, right? This is a pretty good dub album but it can't quite live up to the magnificent cover graphics, in my opinion. Still, someday when they make Vondur In Dub they can just use this cover.
Tappa Zukie Escape From Hell (Stars, 1978) ... Can't argue with skull, flames, and hell. Also, it's a great album.
Bunny Wailer Blackheart Man (Solomonic, 1976) ... Super dark, grim n' spooky cover art. Album title rendered in what's almost a black metal logo style. Artist's name printed in a font quite similar to the one used on Black Sabbath's debut (the exact identity of that font being the subject of some debate, as it happens). Yeah, definitely one that belongs way up on this here list.
The Royals Ten Years After (Ballistic Records, 1979) ... Take away that red-yellow-green border and maybe the dreads and you've got a cover that looks like it belongs on an early Judas Priest album for sure. Sad wings indeed.
Dennis Brown Words Of Wisdom (Laser Records, 1979) ... Meanwhile, this album has art that could do double duty on a proto-metal platter by some obscure, hypothetical Uriah Heep wannabe, whattya think?
Massive Dread s/t (Gorgon Records, 1979) ... Ok, so maybe this one doesn't really look like an actual heavy metal album cover. But, it's certainly rad, right? Furthermore, the brawny musculature and length of hair/beard of the fella on the front – and the size of the spliff he's smoking – would certainly qualify him to pose for some super-heavy stoner metal band's album cover, I think. A great freakin' album, sadly not reissued on cd as yet.
Lizzard Satta I (Trojan Records, 1976) ... Color scheme aside, totally '70s proggy proto-metal lookin' cover art and logo style here, eh? The (sadly not on cd) reggae album is pretty cool but I'd love to hear the imaginary mystical metal record that would share this sleeve in an alternate universe. Maybe something a bit Thin Lizzy-ish? Or, a la Rainbow?
Revolutionaries Revival (Cha Cha Cha Music, 1982) ... These cats show up for a second time on this list with this militant album. It looks more like an action movie poster than a heavy metal album, ok, but the very first track is called "Black Sabbath!" (And another is titled "Death.")
Prince Alla Evil Forces (Calabash Records, 1984) ... Dude's face/expression isn't very metal, nor is the logo at the top, but I think the bloody font used for the album title qualifies this for inclusion here, as do the various examples of evil forces listed on the cover (which sadly aren't song titles). Plus, bats.
Scientist Heavy Metal Dub (Clocktower, 1980) ... Although it fails the truth-in-advertising test (there's nothing 'heavy metal' about the music) you can't argue with these Star Trek themed dub tracks. And thanks to the title & the sorta Pedro Bell style space operatic cover art this had to be on this list!
That's the dozen! I've thought of a few runners-up already but if anyone else has any further suggestions to add to this list, comments are welcome. Number 13 on the list would, of course, be the amazing album by Black Ark Oaken Saw, if only it wasn't just an April Fool's joke. (–Allan)