Get that thing changed out for an Oregon Rim and drum system (not a Stihl one)
when you are at it - Stihl use a "mini" 7-spline system that only Stihl offer rims for on the small saws, and usually want 4-6 times what others do for regular "small" 7-spline rims. The rims obviously are made at the same place, and there is no quality difference to explain the higher price of the Stihl ones.
Curious why you prefer the oregon setup over stihl?