We crossed in the mail.
I saved this tidbit against who knows what sort of need...
Open a page in your browser and enter <http://127.0.0.1:631/printers/Modem_interne> (Edit: Omit the <>.)in the address bar; you'll see
this (one of whose tabs is
this) and maybe find the info for which you're looking. (I don't know whether it will work for you, because the URL suggests that it deals with internal modems, but it's worth a try.)
Edit: And you may find some sort of fax log in Console's sidebar.