I used to own and use a DTP, it worked quite well getting various DAWs to follow TC on a VHS or 3/4" video tape. However, we were feeding those decks video sync, so their playback was pretty steady, vs what you are talking about with the Nagra IVS TC playing back "wild" (unlocked). What will you attempt with the DTP? Trying to make the picture playback in an edit app follow the Nagra TC? If you have the Nagra, the DTP and have already gotten the DTP working with whatever apps you are using using other TC sources then it's worth a try I guess. My advice would be to try and get the audio off the 1/4" tape and then work with it as a digital file vs trying to get anything to sync to the Nagra running unlocked. If you have the picture files in Premiere (for instance) and the camera files have sound on them you could use the "Pluraleyes" feature of Premiere (or Pluraleyes itself) to try to sync audio to audio (between the Nagra files and the camera sound). This is commonly done nowadays and works pretty well as long as everything started out running pretty close to the correct speed.