I think I may have found the problem, there were two bathyscaphes named Trieste and Trieste II. The first named submersible was the record breaking one and did indeed have a "two piece" sphere. I don't know how it was held together but super glue sounds a little bit risky. The joint is always loaded in compression and will actually get stronger as you descend so that not a problem. After the record dive I believe it was acquired by the French navy and used in the Mediterranean Sea. It was finally sold to the US Navy. The US Navy also purchased another "Trieste" built in Italy with modifications to make it more seaworthy. The second ship had a Krupp cast steel pressure hull. The Navy used this craft to recover parts of the lost sub "Thresher".
Both of these vessels used steel shot for ballast. It would not be the first time either Discovery or History Ch screwed up something in one of their films.
Regards,
GtG