Commissioned piece. Ferrus Manus, the lord and Primarch of the Iron Hands Legion.
"The primarch’s armour was black, its every surface
hand-forged, its every curve and angle perfect, its majesty
matched only by the being that wore it. A high gorget of dark
iron rose at the back of his neck and embossed rivets stood proud
on the silver edge trims of every plate.
The primarch’s face was as though carved from marble, his expression thunderous
and his heavy brows furrowed in smouldering fury.
His first impression of Ferrus Manus was of sheer bulk. The
Primarch of the Iron Hands was a brutally rugged giant..."
Blogpost - [link]
I have gotten a few comments on the size of Forgebreaker. It is true it is described as being a huge hammer. Though it is also described as being possible to hold by a marine. This in combination with the size of Ferrus Manus himself (described as towering other primarchs) made me opt for this size hammer.
Following canon is difficult, you have to weigh pros and cons to see what fits best, usually meaning making estimated guesses rather then base yourself upon how you view it in your minds-eye-theater. And even then you have to take other peoples ideas into consideration.
Needless to say, some of you will find this or that detail not to fit, whilst others will find it perfect. I just hope that you like the image...