Yeah, they look kinda big between the collar and the top of the chest plates. By what looks to be a half inch from your pics. Are you just printing out the templates based on the size instructions, or are you actually modifying the size to fit your body? You definately want to use your own size that matches your body. The default sizes I've found rarely fit.
You wanna make sure the top outside edges of the chest plates match the lower outside edges of the collar AFTER you dish the metal if you want a nice symmetric fit.
Another suggestion: Space those plates out a bit more. Leave enough space to be able to put your middle finger between the diamond and the chest. Thumb space between the collar and the gut. Not only will this allow for more movement and cut down on the pinch factor (if there even is one), but it will take care of some positioning problems like the one your having with your collar. Also, pull the collar in closer to your neck. It's gonna give you a better "sealed up" look then letting it sit that far down.
I see the right back piece of the collar is sticking up a bit, so you may wanna curl that more. Probably easier to do that by hand at this point instead of using a hammer.
Ok, those are my suggestions thus far. Awesome weathering man! Really top notch.