After a while, I created the weapon as exact as I could make it to the one featured in said webcomic.
It was a month since I have finished work on the project, I have completely abandoned it, it is not textured or uvw wrapped. I would love to hear some feedback or whether or not I should actually continue on the project.
So here is an image of the reference image taken from the comic, as well as images of the model itself following it.





here is a wireframe of the backpack:

and yes, there may be no way such a weapon could fit in with the engineer's gameplay style, but it was a fun little project to work on.