My starting point for this project is to consider how best to structure the part to be a suitable repair. I think if it is a simple replication of the wooden brace it fail. I don't think the print would be strong enough. Even keeping in mind, or exploiting,  the "grain" implied by the print layers. Essentially a flat, board like piece of plastic would put too much pressure at the bolt holes.

OR it could necessitate making the part very bulky and/or dense. But increasing the size and infill would makes it take longer to print, iterate the design as needed, AND burn up more filament.