Following a protracted family dispute over the estate of Senator Dianne Feinstein and her wealthy financier husband Richard Blum, the late couple’s $3 million collection of Himalayan art will be sold at auction later this month, RadarOnline.com has learned. Over 40 rare paintings and sculptures spanning eight centuries from across Tibet, Nepal, and Greater China, accumulated by Feinstein and Blum over three decades are slated to go under the hammer at upscale auction house Bonhams New York on March 20. Standout pieces from the collection include a late 12th/early 13th-century portrait thangka …