This Tektronix TDS544A Acquisition Board was in better condition than I expected. In fact, its condition was better than the one I replaced. I never expected the conformal coating (very nice touch). Once installed, it functioned perfectly. Now the two initial self-test acquisition errors upon power-up, the signal compensation error, and the huge offsets for channel 1 and channel 2 have been eliminated.
My Tektronix TDS544A is now in working perfectly (all four channels).