The crew wont be going to the Derelict on LV-426, it'll be another Jockey ship, with at least one living Jockey in hypersleep, or they do go to the Derelict and find the Engineer(s) in another part of the ship. I'm sticking with the former explanation.
As an aside, apart from the tusks, I'd say the Giant Head will look more like the second picture from the above post.