faxing from a G3 B&W

Hello all!

In my trusty G3 B&W I have the original internal modem unit installed.
From Panther (10.3.6 now) I cannot send faxes nor receive them properly
(sometimes half a page comes through).

Some have suggested to use Page Sender instead of the built-in fax
capabilities in OS X but I still can't send/receive faxes. Yes, I
switched of "Receive faxes on this computer" in the Print & Fax Panel
when trying Page Sender.

Here's some questions that I can't find the answers to in Google:

- which modem do I select from the modem list in System Preferences?
(now Apple Internal 56K modem v.34 has been set)

- is there some utility or terminal test I can run to check if the modem
is functioning properly?

Hoping that someone can help me or point me into some direction 'cause I
am getting really frustrated about this.

Thanks - Rob