One of the designers did a sheetmetal design with 4 distinct pieces so it is in a part file, not an assembly file as we usually do for a weldment. This leads to a number of questions.
1) How do you show each distinct piece in a drawing?
2) Can these pieces be saved off as individual part files and then rebuilt in an assembly?
3) Is it possible to show a BOM on the drawing of the part file so we can list sizes, etc?
The last question is more general in nature, when did distinct features get added to the sheetmetal package? My last training with sheetmetal was back at WIldfire 2 days. Online documentation is very weak (almost non-existent) on distinct features and how they work.
You may be able to save 4 copies of the file and then delete/edit features such that you would get 4 part files that can be assembled. Obviously the ease with which this might is dependent on the model you start with.
It may be helpful to convert some of the models to solid parts which is supported since Creo 1.
For Creo Parametric 1.0, and up you can convert the metal features to solid
If you are in Creo 7 multibody functionality should allow you to split off 4 parts from a single model. I have not tried it yet so YMMMV.
Are they 4 different separate solid "bodies" in one part with space in between? Maybe you could make a family table out of the 4? I've done that before instead of doing a top-down at the assembly level. It works great for small assemblies, but there are caveats, and rev control can get tricky. Do you have an image to share?
I think your best bet would be to recreate the two simple parts, delete them from the original model and assemble into an assembly.
For as long as I have known, distinct features have been available in sheetmetal. There is an editing feature "Merge Walls" to join the walls. Appears to be an old feature as it uses the old interface.