"I just got this bucket back together, I'm not going to let something tear it apart" - Han Solo

The tool Han is using to put the Millennium Falcon back together with is the same one Leia used earlier before their infamous kiss, a fusioncutter. The prop is actually some type of low power arc welder. The sparks are created when the welder tip touches the metal, completing the electrical circuit started by a clamp attached somewhere on the piece of metal being worked on. Leia is seen removing the clamp wire after she finishes working.

The exact parts of the head of the fusioncutter are unknown.

The main handle of the fusioncutter was made from Luke's droid caller from A New Hope, which was an old Kobold camera flash. There were many Kobold flash attachments used throughout the original trilogy with subtle differences. The one used for Luke's droid caller has a stepped transition on the top section and a smooth bottom with a smooth edge.

The knob was removed from the side of the head of the flash (seen above, the right flash is this prop). The middle section of the flash was painted black by the prop department. It was then wrapped with 3/4" black electrical tape for this prop. The hole in the bottom of the flash is where a screw mount would go in for attaching it onto a camera bracket. A coiled electrical cord can be seen coming from this hole in the bottom of the prop. This is probably the original cord for the arc welder.

On the side of the flash is a rectangular piece that the reflector would slide into. The right side of this piece had a screw and thin long metal plate. These were removed, revealing 2 holes, and a new hole was drilled on the left side at a height to match the topmost hole on the right. These two holes, the newly drilled one and topmost right one, is where an approximately 1 inch D-ring was attached. A small section of the middle of the D-ring was likely removed for a better fit and the two ends fit into the 2 holes.