So I managed to get this guy finished up the other day. It took longer because I could only sculpt a section at a time and then had to wait for it to dry in between.
I added some spikes back in along his spine to make it look a little more convincing and not like the wings were added as an afterthought.
Once I knew where the wings were going to go, I drilled a hole for a flat head screw to go into his torso. Then, after pinning the wings together, I added a magnet to the underside in the small gap between them. I actually drilled out a small area to recess the magent so the wings would sit lower to the body.
Then it was just a matter of greenstuffing the gap between the new wings and the torso while trying to carry over the textur and shapes already there.
Here's how I magnetized the wings in place.
Project Link: Follow my Daemon Prince conversion