Ok, here are some photos of the stuff I had lying around. Sorry if the quality is not good, it was getting dark.
First up this is the 'bone dome'...
Next is the 'turnip' helmet, more correctly called the Crew Guard.
This is type of headset which fits inside it, and the mounting mechanism. This is the latest ANR type of this headset, the earlier type has vents which slide open so you can hear whats going on around you.
In order to use these you need a Pressel box or for the Commanders Box Fixed a Commanders Personal Unit and 10 pin lead (not shown.)
Just for fun, here are some in service photos showing some other variants of helmets and headsets, including the Mk 6 Kevlar in a Warrior.
I hope this helps.
Chris