Tried about 15 drivers to no avail. Couldn't find a reference to the model code anywhere. Then i found this driver. It works. It says it's a Win98 driver but works great on my Win95 (with desktop update) machine. Found on Dell site, description didn't correspond to my modem which is a US Robotics 56K Voice Winmodem PCI (Mediterenneo) internal modem. Hope it can be of some use to others.
Happy driver hunting, Chris