This metal Howling Banshee is an Eldar sculpt from 2005, and was shown as being part number 9947010410207.
Another arm variant of the same body:
Eldar Howling Banshee 3 (2005)
This metal Howling Banshee is an Eldar sculpt from 2005, and was shown as being part number 9947010410207.
Another arm variant of the same body: