I think I have the US version. I gave that big black box away years ago, but there was some hidden setup keys and menus in the machine. Since I never found a manual, I was barely able to change much about it. But if it is possible, then dig out the manual or maybe google.
BTW, the fax tones are international. I've sent faxes to machines overseas with that model. I can't say the same for dial tone. As such, maybe you can change it from touchtone to rotary dial.
I have a Canon Fax 80 faxphone. It was
made in the United Kingdom and therefore
operates on a different frequency than
the United States-made fax machines.
I am trying to find out whether or not
the frequency can be tweaked to allow
this machine to run in the US.