The catalogue with the 3 recently discovered drawings by Rossetti is lot 160
The third from 1870 is called Venus With Two Doves for which Jane Morris is the subject. On an accompanying note William Rossetti wrote that his brother had "thought about painting this."
Statement from Andrew Marlborough from the saleroom.
Just for interest even with a reserve of £15-20k they didn't sell at the auction. I'm still not quite convinced by this but the catalogue was prepared with the help of Christopher Newall who is pretty good.