Converted one of my egret flight shots from the Farm into B&W using Nik Silver Efx and Viveza to dodge and burn. Turned the sky to black ....for the deep contrast.
Vavavavoom! Man, this is lovely! I really like your choice of a silvery finish to this - it really adds so much to the image.
I might suggest smudging some of the more silvery areas so they blend better with the whites. Might try cloning them at 30-40% opacity on lighten and see if you like that effect.