There are multiple artists using this name.
These are photos from concerts where Pendragon played, so they may be of other bands that played the concert as well.
Reading Rock Festival 1983 Aug 26 - 28, 1983 Reading, England, United Kingdom Uploaded by Craig Hatfield
Pic by Michael Knowles from 'Marillion Collectors Worldwide' Facebook group.
23rd National Rock Festival Aug 26 - 28, 1983 Reading, England, United Kingdom Uploaded by Jim Jones
Sounds review
The Jeff Beck Group / Moving Sidewalks / Pendragon Nov 8, 1968 Houston, Texas, United States Uploaded by Zimtrim