If there is a tone listed on the chart which is near in frequency to the
repeater's tone, even if not identical, it still may work.
If, for example, tone 15 was 103.5 and position 16 was 107.0, but the
repeater uses 105.8,
it's still possible that either positions 15 or 16 would work, maybe both.
I've seen it happen on 2 meters.
Good luck!