I saw the ad asking $225. That depends on you. As for reselling it for a profit, probably not a good deal. The frame is the only thing Shelby, the forks and everything else could have come off a beach cruiser, but might be in good shape. A lot depends on seeing it and checking it out. It looks good to me.
However, if it was me and I didn't have a bike, this would beat anything else at the bike shop for price. If the wheels rolled straight and everything was in order, then I might spring for a couple hundred. I'd start at $150 and barter up.
As for year the frame looks like prewar, but I don't know a whole lot about dating Shelbys.