This is how I mounted the camera into the box:
It's mostly an interference fit; the camera boards are wedged in behind the RCA and DC sockets (with a rectangle of thin insulating material inbetween) to prevent backwards movement.
The hole for the lens mount ring is a tight fit to prevent downwards vertical movement, I measured it so that the top of the board would fit snugly against the top of the box to prevent upwards movement and then I glued on the back of the box was once I was happy with the dipswitch settings.
Plus there's a little bit of packing material in there as well to compensate for the iris connector socket, so as to keep it all square.
I deliberately chose the smallest, lightest posssible enclose available to allow me to do this.
No screws were involved in the making of this project.
You can find the RCA socket I used here