For just one sheet you may want to call the producers, Carbon Core, Polyumac in FL, or Nidacore folks, see who they are selling 1" to in bulk in the northeast. Get several names in case some are shut down. I actually buy from Polyumac in bulk, and is cheap to ship from FL to Delaware since its so light. For one sheet the freight might cost more than the product. Does Composites One have a warehouse near you? North American Composites? Both good sources for Mid-Atlantic area but prices can be kind of dear at times if you're not a high volume account. There may be a local boat shop sitting on a load of material that would sell you one sheet if you ask nicely. We sometimes got tools from Mertons, and specialty items over the years too. Good people who may be able to help.
I have dealt with Craig he always goes out of his way and does the right thing,but I thought they were closed and you knew of another outlet on L.I. Its's more of a cosmetic upgrade new top on the wheel house with visor and side over hang I may be putting it off until the end of this season boat is ready to go as is and the way things are right now its easier to wait so if i need a hand I can call in some help. Probably going to use a foam board not coosa but I will still check to see if carry it. also will need smaller piece of coosa to make a small pulpit.
But Thanks for getting back to me and have a safe season