380SLC leans 1/4" to right at rear
 

My 380SLC has a visible lean to the right viewed from the rear. 1/4" measured at the bumper.

Rear shocks are <10k miles old and the car has never been crashed. Rear tire wear is very even and the Michelin MXVs I put on 20k miles ago look like they will go 60k (!) before replacement is needed. Everything on the car is stock. Nonetheless, I feel I should do something about this.

Suspect the rear sub-frame bushings are original - 125k on this 1981 chassis, albeit in a mild CA climate.

Any help appreciated.