Hi, sorry I've only just seen this so not sure if you still need a hand - if you need any particular reference pics drop me a PM and I'll be happy to help
Which version are you thinking of doing? (he looks slightly different in GoF, OotP and DH so that may influence your choice)
Funnily enough, I'm just about to start resculpting mine (as I want to try to get it even more accurate in time for the last premiere) as there are a few things I'm not quite happy with yet.
Was just doing some research to see what needed changing for Voldemort Mark II and came across these two pics which seemed to be pretty close in terms of positioning, direction, and posture.
It's a shame the one of Ralph isn't digitally edited in this pic as it would be interesting to see how mine compared to it then, but it was scary to see how close the posture was!!! lol
There are a few lighting differences too, but you'll get the idea... like I say, you'll have to use your imagination a bit as they've not tweaked the nose, eyebrows and cheeks which makes a big difference to the end result.
I thought I'd share: