(sorry its a passenger side photo, but I put it there so you could see the truck and at least get an idea

<img src="http://www.werrvfd.org/engin13-2.JPG">
Its a 1997 Pierce Responder.
The problem is after the years the Lite Box chargers have started to loosen up. Apparently the other guys tell me that originally there was nuts on the opposite side of the compartment wall that held the screws down and they have just come off. So my idea was just to put a bigger screw. Well that idea was blown all to pieces because I didnt realize how close the tank was to the opposite side of the compartment wall. I cant find small screws that will hold these. Any ideas?
So what would you do?
Nick