2005 E320CDI Turbo Press Hi/Lo Code

[Randy]

Hi, still experimenting with this fine car, 181K very happy miles. Last weekend in the Ozarks, she would set the CE lamp intermittently, and seem to be a little low on low-end torque; fine on reset. Set CE on the on-ramp of US 65 at Branson Monday morning; upon reset at Leslie Shell Station (home of FINE fried pies!) and no more CE lamp remainder of the trip despite hills, Interstate driving approx. 80 MPH, etc. Usually the code now is "turbo/supercharger low pressure", haven't seen a "high pressure" code lately.
I think perhaps her turbo vane actuator is becoming more and more intermittent. Does anyone know a source for rebuilt actuators they can recommend? I am willing to swap it out after 13 years and take a chance that's the problem. I am also willing to listen to and consider any advice or comments.