I just went to GV Bikes and asked if there was any info on the pillion. He had one last week, and I saw a pic but it was a very dark b&w. It bolts to the bracket under the solo seat, also onto the frame where the shocks are, and suspends over the fender without attaching to it or requiring any new holes drilled.
Looked good from what I could see. Bit pricey though, 120+ shipping and tax so roughly £150 plus installation if you chose not to do it yourself