I would replace it with one of the aftermarket concaves that have opened up the concave all the way up to the hump, adding more crossbars, more area for threshing. Greatly improves the thresh.
I use the St. Johns cylinder and concave. Best money spent on the l3. This year I averaged 8 acres hour in 60 bu wheat with 22' header. That is stopping to unload. My speedo showed 4 mph.