Eternus Armor Bits on Contemptor

[FoursCompany]

I’m curious if anyone has used the Eternus Armor bits from Pop Goes the Monkey on their Contemptor dreadnaughts. I’d like to use some of the bits (heads mainly, maybe shoulders or greaves also) on a GW plastic dread to just add some custom flair. However the heads look like they might be too big, same with the other pieces.