[Stuart Simpson] “You can edit with them, but if there is no BITC you’ll have to do shot descriptions and then match up by hand! “
That’s what I’m saying about the internal TC in FCP.
If each of these dubs is of continuous rolling footage, you can use a visual cue (first frame of second scene, for instance, or anything in a scene that is very distinctive) to call “00:00:00” on the Aux timecode of FCP, then you will have a time mark to call “zero” on each film.
But, all of this is moot if you are not going to scan everything on a film clip to high rez.
Without a locked reference, the off-line is useless (except to see what the finished cut MIGHT look like.)