Looking great!
Something I have done to ensure the cod piece sits high enough, is buy a cheap pair of braces (Gordon Gekko style haha) and attach those to the cod piece by gluing small strips of webbing to the inside of it. I can then put on the cod and itll be held in the right place by the braces.
You might also want to look at the scale of your chest, which doesnt quite look wide enough to meet your shoulder bells, giving the other parts like the abs and helmet the impression of being large. A couple of extra strips to fill in the gap between the shoulder and chest might help here.