I have progressed to the point of putting thwart seat braces in and one of my stern seats, an outer one, does not sit level and has a bit of a bow in it running lengthwise (center bowed down so it rocks on  a level surface). I can adjust the bed of braces to accomodate the bend, and then plane it down level. But I was wondering if there is any hope to somehow get it to bend back straight? I assume those are cedar panels, not sure if they will bend back over time if I weigh them down on a flat surface. Have a few weeks before I need to actually install the seats so I can try ideas. any other tricks to deal with this sort of thing?

All three seats have ended up sitting at somewhat different levels vis a vis the others (with different heights at different spots along the edges), so there will be some planing needed here I suspect.

Thanks