I created a part file using weldments, PartOne.  I selected some of the weldment bodies, right clicked, selected "Insert into a new Part" and saved it as PartTwo.  I created drawings from PartOne and PartTwo.  This all worked well.

Now there is a revision and an additional piece is added to PartOne that needs to show up in the derived part, PartTwo.

How can I do this?

Thanks!