Hi Imthiyaz,
Nice idea! However, having more granular access control within the Team Server is currently not supported. The only options now are: you can read and write the whole repository or you don't have access at all.
There is a feature request written in this idea to grant only read access to the repository, but that doesn't suit your need.
You can however verify if not someone changed accidentally those completed modules. You create a branch of an old version, and next merge all changes done afterwards as a single change into your new branch, this will generate a list of all documents touched during the changes.
Good luck!