Let me add , that for us that rebuild/refurbish parts and assemblies , they are very cool in the sense that you can get bushings , brushes , kits ,etc. that at one time were available here , but lomg since gone.
If you do get into this scale of repair , it is sooo nice to rebush a $150 part for $4 worth of bushings and wind up with a rebuilt part.
As a veteran tech , I find them invaluable and one of the reasons I have beeen a Benz fan for 40 years is that these chassis were built with the mechanics in mind , by design, to have sub assemblies that can be repaired. ..and SLS know that and continues to supply the kits.