RARiddle,
Sometimes you have to resort to making a duplicate of the thread from cerrosafe and the female thread in the other part. The female thread should be cleaned and oiled first. If you make a small dam with whatever is easiest for you, you can have a war to unscrew the duplicate. If you can't get it out, or break it; you can melt it out with a heat gun on "low" setting, or maybe some hair dryers. Once you have the duplicate, you can measure the diameter and pitch in the normal way.
Mike