Due to previously leaking chain plates, the interior bulkheads on my C22mkII are in need of replacement. I plan to remove them and use them as a template to make new ones during the winter. So, two questions. First, does anyone know where to get marine plywood in the NYC metro area? Second, if I remove the old ones at the end of the season, will it be OK to leave them out until spring. I keep the boat on the hard with the mast up during the winter. Any advice will be appreciated.