OK, I used Avidemux to stack the fields of that sample. I can't find any pattern, every field is smeary. In no instance does a single video frame, or even a single video field, exactly correspond with a single film frame.

The bottom field seems to be a bit ahead of the top field, too. Look at how you can see both sides of the shot change at the same time:

Since this telecine has no pulldown and no discrete reproductions of individual film frames, I'm not sure if this can be IVTC'ed. The closest I could think of would be to toss out the bottom fields, resulting in a progressive, half-resolution image. It would still be smeary, but there wouldn't be any interlacing, and it would also "unsqueeze" the picture.

I will say though, this sample looks great for a 70s bootleg. I can definitely see a marked increase in quality from the original capture. And I love the color; this is probably the closest representation of the timing of the original Eastmancolor prints that we'll ever see.

I can't wait to see how this project further progresses.