Something I learned from floppies is that different drives (or decks, in this case) have different read characteristics, so the "bad" segments of tape are different depending on what you're playing it back with. I once was able to use that random fact to restore some data off an old floppy - it took three drives/PCs, but I was able to get a clean read of each block, and piece them together.

Extending that to DV tapes: the DV format is interesting in that every frame is a keyframe, and encodes an entire image. That's in contrast to H.264 and friends, where frames can be predicted, and/or just the difference between a prior and future frame can be encoded. DV also encodes a timecode into each frame. So if you had multiple DV decks and were able to get a bunch of unclean imports, it seems like it'd be trivial to write a small tool that grabs all of the clean frames from each and stitches them together over the gaps in others, according to that timecode.

(Disclaimer: I've never done that, this is a pure spitball.)