Question re: broken wood planks

On a pre 1900 crate I got, a base plank has a section that broke away over the years. The broken piece broke away lengthwise. Do I leave the original piece in place that broke, and as a result, leave the hole?

 

Probably, but a pic might help to see what we are talking about.

 

Pic

 

Kind of hard to tell what I am seeing on my phone. If the missing piece is on the bottom where it won't show, no harm in replacing it. I would use old wood if possible and cut it to fit just the missing part. I thought it was on the side based on your description.

 

By enlarging, I see that there is a jagged piece missing that is visible from the side. I would remove the remaining bit and move the center bottom plank to the edge where visible. You could, then, fill in the center missing piece with a new piece, preferably with old wood.