I just renamed the copied part to something else, then generated a new part within the ePDM with the part number that I wanted to use, opened the file in the editor, added some geometry and a configuration, saved/checked-in, then went to the ePDM and was able to update the newest file part number and the system took it okay. This tells me that there is not a naming conflict per-se, so it is looking like something internal to the original part and the updated copied part that are in conflict with each other.
So, it looks like I will be generating a new part from scratch to get done what I need to get done in the manner that I want to get it done without using solid bodies. Oh well, time to bury my head in the editor for a few days. Probably better to do this now rather than later when I've got the part included in 20-40 different assemblies so I don't end up with corrupted issues down the road.