If you have no backup of the project repositories, you will lose some of the items stored there. Items such as attachments, UFT scripts, workflow customization, and so on.

In many cases, the assets stored in the repository are not that critical. Create a NEW project using the OLD project's name. Once the project has been created, you will need to Remove it from the projects list in Site Administration. Access the project repository folder and edit the dbid.xml file to reflect the OLD project's database schema. Once the dbid.xml file has been updated and saved, you will then need to restore the project in Site Administration and run the Repository Realignment on the project.