follow that link to the picture of the shotgun off google
If you raised the bullets and made them a bit larger round then you could prob put the disc drive there, laying atop of the shotgun including the bullets on the side of the shotgun to help with the width that would require of the disc driver
You could shorten the stock and make it thicker for the hard drive? possibly the port also
I was thinking the power button would be located on the front sight or mabye the barrel?
Also since 2 barrels and between the shotgun shot would be a good spot for the hardrive
If there isnt enough room to put everything then u could possible put it on a base of hand grenades?
http://www.airsoftatlanta.com/images/new_12_grenade_jpg.jpg --- thats the link to a grenade
of course that would be a different design but if u didnt have enough room in the shotgun then u could put the shotgon on a base of grenades or a concrete block, like its recently been used after a battle and a soldier had to run and leave it behind .... Hope ya choose mine!
P.S. - srry i couldnt put the images on the post - and yes i read the steps u put in your thread americanfreak