[Jamie]

You can try that, but in my experience, you can't bury the cracks with dark toner. If you try, the set will just be too dark and possibly muddy looking on the area you try to hide. If you've sanded as much as you feel safe doing, and the cracks are still visible.. either get new veneer, or just refinish as if they did not exist. You'll still be able to see them, but it looks better than a very dark area.

Get some timber mate wood filler and work it over the cracks. Then smooth it with fine sandpaper. It accepts toner quite well and you'll hide the much of the cracks.