What's your reasoning for the 'yah right' part in your post?
66-67 Acadians and Chevy II's are the most sought after years for that model, and they command a higher price because of that fact. I'm not surprised by the 40k appraisal myself. My 66 Chevy II SS appraised for over 52k before I did a bunch of upgrades to it, so I'd say it did appraise for what he says. Anyone that has a professional appraisal done gets the paperwork to prove it is legit anyway, so you would be able to call BS if they couldn't provide that proof.