Thanks guys, I'm glad that you (still) like them.
Dave - the Explorator's autopistol is just a cut down Arbites shotgun, mounted on the Eversor assassin's right hand (with the magazine still attached.)
The Psyker's autopistol is a more complicated beast, consisting of parts from a plastic Necromunda Goliath autopistol and autogun, an autopistol from the 2nd edition 40K Space Marine close combat weapons sprue, a piece from the back of a current Space Marine boltgun, and the reciever and grip from the large shotgun that came with the Imperial Weapons sprue. It is built around the left hand from the Bosun/Bodyguard model
Van Helser - that hybrid isn't naked - he's wearing a loincloth.