I really liked this artwork and wrote some music using the image for inspiration. Would it be OK to include the image on my sound blog (thinkingsound.wordpress.com)? I will credit you and have the image go to your deviantart page.
Usually I add photo refs on an overlay or soft light layer then erase parts I don't want and/or reduce the layer opacity. Finally I will paint over the top so it blends in with the rest of the painting.