I've tried imagining Carl singing on many of the songs. Especially the chorus to "Shelter".
I agree. When I listen to that song, I can't help but imagine how Carl would have sounded singing the chorus. In fact I think Carl would have sung all of Foskett's parts plus taken over some leads. With Dennis, I can imagine him singing lead on a song that would fit in perfectly with the suite at the end and for backing vocals, he would add to the blend.
Well, one can dream...