Looking good.
I agree, the black series buckets are way too big... definitely makes the armor looks funny on you.
As far as the ab "buttons" they look good to me.
Keep in mind, that if you wish to go to Centurion Standards:
Abdomen armor buttons are integrated and painted directly on the armor.
No separate buttons are allowed.
Just keep that in mind if you wish to shoot for more screen accurate buttons.
Other than that, keep up the good work.