A tedious job at best. I wonder if they used, or are aware of, a technique used by some ingenious archeologists in Israel. (Saw it on TV about a year ago.)
These geniuses had a computer program written that would take scanned pictures of pottery shards and trying different configurations, swapping the edges around until they fit - all at computer speed. Using something like a paint-by-numbers approach, they then took the physical pieces and matched them up to the computer screen and had the pot assembled in no time.
Now if only they could do some automatic transliteration of all those cuneiform tablets.
actually, not that tedious, the hardest part is getting the non-permenant glue to stick, on pot sherds it is rather quick but on metal or stone not as quick. at the UofMN I worked with the 3-d imaging software, it takes between 5 to 15 pictures of each piece. and about 10 minutes per piece once you get your set-up done. A good tech could digitize that mask in an afternoon.