I do not know the exact reason for building Erebor gear version of Dwalin. Of course he is a cool character and has small yet important role on the last film, but I think I ended up building him because of the pieces available. I got 100 of those short chains for 9€ from Bricklink bulk store via member of our LUG during an exhibit at Imatra on February. I also got some olive green car hood slopes from LUG support bags and traded a few from my LUG members and then just began working on Dwalin, beginning with the upper torso and the shoulders (the amount of the chain enormous; 54 at the end) and finishing with the boots and the axe, as usually.
The torso came out very nicely. It has tons of SNOT, and the shoulder connection is not very ideal (Two half-pins and half of an axle) but the finished model is quite sturdy. Dwalin has more depth than your average dwarf, which is ideal as he's the muscle of the group. The torso is solid and heavy, being full of brackets and SNOT bricks and layers of plates. Olive green cheese (thanks god it's cheap) and the car hood slopes ice the cake. Dwalin's mantle has a very pleasing colors, olive green and browns.
The arms were a bit problematic, but arm bands saves the shape of the lower arm; Another solution using 2x2 round tiles with holes and travis bricks, very cool pieces both of them. I came up with those when at work. Minifig legs work as elbow joints, just like on Ridcully and Bilbo. They are sturdy joint pieces and available in pleasingly wide array of colors.
The axe was very interesting. It is not so visible in the movies where the colors are not that bright, but according to Weta's Chronicles books the axe's blades are green stone native to New Zealand, so I ended up making it dark green. In addition to that, the shape is quite strange, having bars on 45 degree angles rather than 90 degrees. I fiddles with it a long time and finally found a solution using travis bricks, bars with clips and, as the seed parts, magnifying glasses; Clips attach nicely to their edges. The result is quite cool, if you don't mind me saying.