This conversion is a lot of fun, I tell you! I found some free time and got some more work done. Enough talk, pictures!
I used some plasticard pipes to make an arm. It will of course get the green stuff treatment. Random bit (from Storm Talon maybe?) and two pieces of pipes to make the engine and exhaust.
I did some more Green Stuff work, filled up some gaps and smoothed out some of the old work. It still pretty rough. I added some wires coming out of the spine.
Lascannon. Pipes, bits and green stuff.
The arms are detachable. I think that the pose is ok. The leg is there just to give a sense of the size and bulk of the Helbrute. Still a long way to go but it is getting there.