I don't understand how watermarking them will help with tracking. Do you mean that when they are printed out you would know which project the belong to?
We have something similar with unique projects where we reuse components as much as possible and create new ones if needed but we don't add any watermark to the pdfs. As the engineers work on a project they will create a virtual file of all of the pdfs needed. They can be printed if needed. But more importantly, this links the pdf to multiple projects and you can trace linkages if needed.
I think you have two options, that come to the top of my head. Both of them would probably require creating a configurations in the existing parts/assemblies with the new project number. Unless you will not use the old number again. Then you could just change the Project number in the file and save it. The file history would always contain the versions with the old part numbers.
- Set the vault to allow PDF's with the same name. Save the new configuration with the name and new project number. It would have to be in a different folder.
- Check out the PDF and save the new version over top of the old. In SWPDM this will allow you to get the previous version with the old project number if needed, but it won't have as much opportunity to accidentally send out the file with the wrong project number on it.
The second option would be my choice.