HI Dana, welcome aboard! Wow, I see you're actually in Westerly!
OK the usual answer is "Condition is everything". That guitar looks like it's been pretty well kept from the photos. Are you the original owner? That'd count for a lot for a guy like me. Also sunbursts are very desirable to a lot of folks and somewhat uncommon, so that's a plus. And original case is a plus, too.
Are you familiar with some of the finer points of gauging condition like checking the neck angle, and measuring the bridge and saddle height, and action? You're likely to get asked those questions by serious buyers.
OK, those caveats out of the way, I love D40's and those very late Westerly examples are very unusual or having a narrow headstock. Traditionally they had "paddleheads", wider at the top. It's another unusual detail that could actually be desirable to a guy like me.
Also, that period of Westerly production is generally recognized as being of very high build quality. Lot of hard-core Westerly fans out there, or am I preaching to the choir?
All that is background for my informal guess of $1200 all day long, assuming it's in very good nick. '01 price list shows 'em at $1499.00.
I'm not in the market but I bet it sounds great and I'd love to check one out someday. Hope that helps!