There is a webpage that deals with "win modems" and this would appear to fall into that category. Here is the link to that website:
http://www.linmodems.org/
As for a few other things...
There are 2 seperate distros, 1 is RedHat and another is Mandrake. Either way, you have quite an old copy of either one there, and should go about getting an updated version. You can download "iso" images of the cdroms at mirrors located on each of their websites;
www.redhat.com and/or
www.mandrake.com
Once you download the images you can burn them to discs with a CD burner and A burning program that supports burning image files.
As for the dialer, there are other options, but like I said, you should get the updated versions first and then go from there.
This is my idea, let's see what others think though, someone might have a better/easier solution for you.
Cool