Quick sketch I drew up. Using some L shaped steel pieces as the main lateral brace. They're about 2mm thick. Also 2 5mm thich flat pieces of steel. They will need to be the same thickness as the wood piece from my mockup. I can always grind away some if need be. This will need to be welded for maximum strength. Then I will drill and tap some threads for the screws. Haven't decided if I will weld to the seat frame or just bolt. Leaning towards the latter, due to high temps and possible dam