In reply to Cuthbert:
I skied it in 1966, the same year that I skied the Haute Route.
We did it from the col below Dufourspitze as shown in the photograph posted above, having just summitted Dufourspitze.
It would be totally different now, but I recall the descent through a heavily crevassed area of seracs being quite deceptive from above requiring alert route finding.
At the bottom we were able to ski right down the glacier and the woods above and into Zermatt.
By far the longest ski decent I have done