{OT} BFG Constuction help?

Today, I recieved my first three plastic Imperial BFG ships, thanks to a
judicious use of Bartertown.  Everything is there, the price was right,
and
the ships look pretty darn good, with extra bits and all.  However...I
didn't get any instructions with these guys, and there's a few things
that
I can't quite figure out.  On the gun sprue, there are four short little
things (about half the size of the antenna mounted atop the ship) that
look
like guns.  What are these, and where do they go?  And what fits into
the
square holes on the underside of the ships' "wings"?

To avoid boring the list as a whole to death, please e-mail me directly.
Thanks for the help, all.

Now I just have to figure out how to paint them....

John X Crimmins
johncrim@voicenet.com
  "...is one of the secret masters of the world: a librarian.
They control information.  Don't ever piss one off."
  --Spider Robinson, The Callahan Touch.