I've been reading up on this too. It seems he built John Paul Jones' 8 String.
Frome the Shining Star Website
BecVar's art and skill in the making and embellishing of instruments, along with growing recognition for his guitar compositions, brought him to Northern California in the early '70s. He set up shop in Sonoma where he became well-known as a Luthier, making one-of-a-kind electric guitars for such world-class rock 'n' roll bands as The Who, The Peter Frampton Band, Led Zeppelin, The Jackson Five, Earth, Wind & Fire and Carlos Santana. One of his guitars, ornate with exotic inlay and carving, now resides in the permanent collection of New York's Metropolitan Museum of Art.