This was the route I took. I spent a year waiting for the right 552 to come along - early model, unserviced, but of known provenance - then had the full monty service done by AV Options in Chicago.
One interesting detail is that, in addition to the PS recap & DR upgrade, they offer a rebuild service on the head unit which includes a new display board. At the time, this seemed (maybe) excessive but, given that I plan on the 552 seeing me out, I went for it. Considering the comments on the “How many defective 552s” thread, I’m glad I did.