That Trust badge looks to be the logo of this French band which formed in 1977. The Black Sabbath one has the S in the style they used on Sabbath Bloody Sabbath (1973) and Sabotage (1975). So clearly not from the Isle of Wight festival, but rather mid-late 70s at the earliest.
So not really relevant, but Black Sabbath did play a small gig on Isle of Wight the same month as the 1970 fest:
Date: Saturday, 1st August 1970, 7.45 - 12 Midnight.
Venue: The Music Box, Ryde Airport, Ryde, Isle of Wight.
Support: Perkin Warbeck, plus a guest group, plus DJ and compere Spike.