Overview
You have web services published on wssd on top of sbm/services on the portal server, however, those services don't have any user authentication to invoke from third-party vendors. You want to know is there any possibility to disable service in the dashboard but still have it available to invoke from a third-party vendor.
Information
There is no option to authenticate the services before displaying them on http://*.com/sbm/services.
You can disable (unpublish) the services that you don't use but you won't be able to invoke them once disabled. To unpublish the services refer to the Business Manager First Steps Guide.