I agree with Mr. Fixit - this stuff will clean up fine - a bit of time in the dunk tank at the machine shop and good as new. Don't let the rusty look deceive you - this is a likely gold mine here.
As for value? - well, here is ONE set of heads that sold yesterday, so figure from there....
http://cgi.ebay.com/ebaymotors/ws/eB...category=33617