I HAVE used this driver for Windows 95 OSR2 (Installed and tested under Windows 95 OSR2).
I found it works best if you set the modem for PnP mode. (REMOVE ALL the jumpers from the COM jumper block. 2 row of 3 pins.)
I modified the wave inf to add the modem description. (The inf is supposed to be generic for all 33.6 voice modems) The file is from 3COM but was on the USR site as a generic download.
If you want the modem to be on a particular com port you may have to mark any other unused serial port i/o addresses as reserved in device manager.