I am doing an edit using footage somebody else shot and all I know is that it was a 4:3 camera.

I have no idea what the best setup would be for this in FCP but would ultimately like to be able to enlarge the clips to a standard 16:9 frame without it disappearing behind it's own borders when I motion zoom it.

Many thanks.

You could put the 4:3 clip in a 16:9 sequence and then nest that sequence into the one you have applied the motion zoom to.

Thankyou, will give that a try.