Today's often used playback decks of tapes recorded on old field recorders such as the Sony TC-D5M, or Marantz PMD430 are Nakamichi's with automatic playback azimuth such as the Dragon or CR7A. Some prefer the 582 or 680 series for their manual azimuth adjust on front face plate.
I agree with Ozpeter, if one could have the same deck the tapes were recorded on, serviced, in good working condition, and the azimuth set the way it was when you made the recording would be ideal.
I own two Nakamichi LX-5's and 2 CR5A's and take the doors off to do manual adjust.
The Tascam 122 was reliable back in the day and should be AOK if you have access to one that can be or is serviced. Remember, most of this stuff is 40 years old or so!!!
Let us know what you decide to do.