Do you still have the saw? I am looking for parts as well. If this is a model 113.29991 then original rip fence had a pinion gear that rode the teeth (and the bar would be steel).
The pinion on my rip fence is stripped but it works OK now that I removed the gear.
I am looking to replace the gear, get another extention, get a dado insert, and get the orginal safety shield. Niether Sears or Ridgid(formerly Emmerson) have the parts or can refer me to anyone else. I think that I will be forced to canabalize onther saw if I can find one.