On the Shelf 'The McCartney Legacy: Volume 1: 1969-73' By Allan Kozinn and Adrian Sinclair Dey Street: 720 pages, $35 If you buy books linked on our site, The Times may earn a commission from Bookshop.org, whose fees support independent bookstores. He has just spent eight years working with Adrian Sinclair on “The McCartney Legacy: Volume 1: 1969-73,” the first …