Eric Sloane Original

You can go to AskArt dot com or just google his name.
Lots of info comes up.

Eric Sloane was an author and artist who made a career in being an artist and illustrator for Americana. He wrote several books like "A REverence for Wood", which was a book about barns and furniture in colonial America. He also wrote a book on the "Tools of Early America", in which he presents a history of woodworking tools that built the barns and furniture. He did a lot of painting in Bucks County P and his original work is all over in galleries and museums in and around the lower Delaware Valley. His work is evocative of PAul Detlefson or some earlier artists of the "Bucks County Plein Aire"
Ive seen his work all over the map as far as price, and usually big pieces that are arranged with the long axis being horizontal are the highest price realizers. Ive seen his work from 2500 to 50000$ so, if you have one thats as big as you say, you could have one of the goodies. (I dont know how his seascapes draw prices since hes best known and collected seriously for his barns and landscapes).

I would spend some time to find a decent auction house in your area (or look up on some service like auctionzip or a trade paper like MAINE ANTIQUES DIGEST, and see if you can get it appraised by an auction house that would want to sell it for you.) REmember, an auction house will operate to sell to the highest bidder unless you post a "reserve" on your piece. Also, the auction house will charge you anywhere from 25% to 35% of the sale as their commission, so a 50K sale will realize you from 32000 to 37000.
Good Luck on your adventure.