It was already known and therefore no surprise. The power valves didn’t look that good, 3 of the 4 sliders already had a slanted center pin, so these need to be replaced.
Power Valve Middle and Top Parts 
Damaged Power Valve with metal residues 
Damaged Middle Part of Power Valve 
Damaged Middle Part of Power Valve
The problems of the original sliders of the RS 250 are widely known: The pin in the middle part starts to tilt after some time and slowly expands the hole. There are several scenarios afterwards, all of which end with metal parts ending up in the cylinder. Also the upper part can break next to the slotted hole.
There are several ways to deal with this problem: Middle parts made of one piece, reinforced inserts for the middle part, reinforced upper parts or completely new manufactured outlet slides. These Cougar Valves are very expensive, with only other mid-sections the problem with the breaking tops is not solved.