Have you read through the ANH Hero DL-44 research thread (all hundred-plus pages of it)? There's debate there as to how much the stems of the pushrods need to be cut for the "iron sights" on the bull barrel. The "catamaran" part isn't used for the DL-44. And you need three engine cylinders to chop up into the magazine grille. It uses the lower, fatter section of each, the bottom third flippped upside down. The upper third is set back slightly from the other two, and the upper and lower sections are both tweaked to a slight rearward angle:
http://img43.imageshack.us/img43/9963/kyrtysoverlaycopy.jpg
Here's the relevant post in the thread I mentioned, and
here's the final clear 3D model to show you what it should end up looking like. Read through he whole thing when you have time. It's worth it for understanding this piece and the ones related to it.
--Jonah