This marine is going to serve as part of an Honour Guard for a forthcoming Captain model, specifically Commander of the Fleet Borya (part of the background I have been writing for my World Eaters as I build up the army.) As such I wanted him to be in a ceremonial form of armour, rather than something which will necessarily be used in front-line combat.. The marine would most likely be a veteran to be given the honour of acting as an Honour Guard, and would take this role in meetings with other Legions, components of the Great Crusade, or maybe even when meeting lost offshoots of humanity as part of 'diplomatic meetings'! The purity-seal esque scrolls stuck to his chest are a reference to one of the Horus Heresy book series, which mentioned scrolled 'oaths of the moment' fluttering from the chest plate of a World Eater captain.
The model itself is a mix of different conversion ideas. The biggest contribution was the blog My Wargame, which has excellent tutorials for all the various earlier marks of armour, and one I can't recommend highly enough for anyone wanting to make their Pre-Heresy armour as accurate as possible!
I did toy with the idea of using a complete Mk1 armour, but this as this is not completely enclosed and so opted instead for one which mixes mk1 and mk2. The polearm/chainaxe is a mix of Bretonnian Halberd and Forgeworld Chainaxe, the bolter and backpack were made using just standard components using the tutorials from My Wargame. The shoulder pads are an excellent new release from Chapterhouse Studios, and the helmet is part of the 'Steam Knights' range from Maxmini. The chest piece is a filed down mk4 torso from the Forgeworld Red Scorpion upgrade pack. Finally, I added chainmail with greenstuff to tie the model in with the rest of my forces and to give it more of a 'World Eater' feel!
Eventually I hope to have a squad of 5 marines, armed and armoured in a similar manner, and most likely using this model to represent Commander of the Fleet Borya (with a few bells and whistles added, and the sword changed to a chainaxe of course!).