I'd leave it alone for now. I like it a lot myself, and have no idea if it is worth significant money - but it has aesthetic value.
It could be worth getting appraised by one of the major appraisal firms, and that costs money, guessing a few hundred dollars.
Lightwizard is a fellow who posts on a2k who knows a lot about appraisal but he hasn't posted lately.
I'll try to see if I can find a link for what he has said about appraisal.
Or... someone else may have more knowledge than I do...
OK, here's a link, the first one in list I found by searching 'appraisal' and lightwizard as the author. Not exactly the same circumstance, but may apply for you -
http://www.able2know.com/forums/viewtopic.php?p=626945#626945