As i understood you want to let users with 2.55 connect to your 2.60b server only, normally you need to delete mp_bin.pk3 , pak1.pk3 , pak2.pk3 from your etmain folder to be able to let users from all versions connect.
If you want to have Real Time Information, you need to contact paul @forum or @xfire (forum: Paul , xfire: trackbase)