I dunno... listen to "Fireball" by Deep Purple, sure sounds like double bass (though films I've seen from that time only show a single bass on Ian Paice's kit).
if that aint double bass it's some pretty shnazzey drum work for sure.
Overkill by Motorhead has some double bass work as well . that's what 1979 I believe. so does Exciter by Judas Priest. Les Binks broke out some 70's blast beats himself. Dissident Agressor (later cover by Slayer and barley changed) has some double bass beats going as well on sin after sin in 1977.
Double bass drum techniques were first used by artists such as Ray McKinley as far back as the 1940s, and then further pioneered by artists such as Louie Bellson in the 1950s and popularised in the 1960s by Ginger Baker of Cream and Keith Moon of the Who. In certain types of metal, the drummer plays a constant stream of rapid-fire notes on the bass drum, and the ability to play evenly at extremely high tempos is prized (as exemplified by Canadian band Eudoxis whose bass drums measured six feet in length). While metal drummers are stereotyped among some as focusing exessively on double bass speed, other metal drummers of various genres, such as ex-Blind Guardian drummer Thomen Stauch, Dream Theater drummer Mike Portnoy (who could also be classified as a progressive rock drummer), and Cryptopsy's Flo Mounier are also known for varying their double bass patterns and using them to interact with the other drums in a complex and creative manner. Additionally, some drummers, such as death metal drummer Derek Roddy and rising death metal star Tim Yeung are notable for being able to execute complex bass drum patterns at very high speeds while playing independent patterns in the hands.