Cleaning/updating an older amp

I'd like to know if anyone has any experience in cleaning/updating an older solidstate amp.Specifically an Audio Research D200? It's an older amp from the 90's. I dont't want to send it to Minnesota if I don't have to. The amp has no issues but alittle refreshing is needed after all these tears.
I have a pair of Genesis Servo 12 subwoofers. Each sub has its own freestanding, dedicated amp/crossover unit. After 15 years, I sent both units to a local used stereo & repair shop. They removed the board for hydrosonic cleaning, replaced a number of passive components that had either developed small leaks or got "long in the tooth" wide more current, but still modest parts, tweaked the power supply and output stage, etc. Certainly not a big time mod with V-caps, new solid core Ag hook-up wire, WBT parts, etc. More of a "freshening up" of two SS units.

I couldn't be more pleased.

If you are commited to keeping it and if you have a local shop that is competent, I am sure they can freshen up an older SS Audio Research at a very reasonable price.