nice to hear you're involved with this great project...
The old photo with the band beyond the Roundhouse was probably taken by someone in Blackhill Enterprises agency staff, because it was taken just after the first Harvest artists showcase on May 30th, 1969 (two shots of the band on stage are on sale at Repfoto site - https://www.repfoto.com/index.php6).
The original photo was published officially for the first time on EMI-Harvest 5CDs-Book anthology "Harvest Festival" published in 1999, so you could ask them.
On the same book you can find also photos of Michael Chapman and the Edgar Broughton Band taken in the same occasion.
That's all I can tell you.
Please, let me know if you will use the TEB photo for your project because I will promote it through Ghettoraga Archive.
Luca Chino Ferrari".
no©2017 Luca Chino Ferrari (unless you intend to make a profit. In which case, ask first)