Hi Charlyd,
Maybe the contents of a TDS7404B (you have these) its EEPROM are a solution. For the TDS5000 and TDS5000B Series these are interchangeable. Experience of andy2000:
" I copied the contents from a good TDS5054B to a new chip, and no more error. Obviously, the calibration isn't to spec, but it's amazingly close, and good enough for casual use. I was a little surprised that the B version's data was compatible with the non-B scope. "
Succes,
Calibrationfixture