The __db.00* files are not replicated database files. They are internal Berkeley DB files that back our shared memory regions and they are specific to each separate site's database. It is expected that they can be different sizes reflecting the different usage patterns and potentially different configuration options on the master and the client database. To read more about these files, please refer to the Programmer's Reference section titled "Shared memory regions".
I am assuming that your replicated databases are the QM* and Qm* files. These look like they are the same size on the master and client, as we would expect.