[Arran]

 I think it would be just as much effort to make a short piece to fix the chipped area as it would be to make a new strip of wood to replace that side of the grill bar. What I don't know is how these bars were constructed, did they take a single strip of wood for each bar and cut that profile into it, or did they make each bar out of three strips of wood and tack them together? If there are small nails in the edges of each bar then it's the latter, which means you could probably pop the strip with the chipped edge right off, if not then you could take the grille bar in question out, and run it through a table saw to remove the old edge, then make a new piece and glue and nail it on. Regardless of what you do, if you can remove the grille bars it will make it much easier for you to work on them, the bar to the left of the one you asked about  looks pretty banged up as well.
Regards
Arran