Here's a link to the Ref CD (with recognition to Brak's Buddy for gathering the info and Sergio for the hosting) showing my thoughts on how the connection between the collar and backplate works.
Picture 195 - Collar/back join
Here's one showing the cod.
Picture 594 - Cod
The only differences I can see are underneath, it goes a little further, and the raised section on the front is a little more raised. That may be down to the angle of the photo on the MLC, as it's pretty straight on.
Also, it goes round the sides a little more to meet the kidney/butt plate half way round. I saw a photo of that which I'll look for and link to once I've posted this.
::EDIT - Found the one I was looking for
Picture 594 - Cod + butt plate join
You can just see a bolt (should be the same as the collar studs) and I recall this holding the cod piece to the butt plate, one overlapping the other similar to the collar/back plate, above - END EDIT::
The shape of the collar, back and shoulders looks good to me.
The only other observation is in relation to the chest armour. The protrusions above and below the diamond, where they almost make the left and right chest pieces meet, seem a little rounded, and ought to be slightly squared off. It might be down to the resolution of this crappy old laptop I'm using at the moment. Can anyone else with a better machine (probably all of you!) see it and agree/disagree?
Nice work Mardon!