I have had the same problem finding parts. Unless you can find them on ebay try sending a message on Lunds Facebook page. They are really good at getting back to you.
Check ebay and search for Lund. Then check with a seller named Great Lakes Skipper. I think he buys overstocked and or out dated boat parts then resells them. I see tons of lund stuff listed by him. I dont know if he will have what your looking for ,But worth a try.