I feel like the chapter master will be a tough sell of getting a new weapon on him without it looking silly if you don't use a new chest plate and try to position his arms differently. Much cutting. I head swapped mine to use as Azrael, used his fancy helmet on the mungrin from the Deathwing set as his bearer. The librarian is easy enough, his sword arm is a separate bit. He'd be cool to see a force axe on, for when you want that AP2 instant death action.