Don, I didn't check on all the titles, but it looks like the African Queen was released on DVD at some point. Here is one current auction (not mine):

http://cgi.ebay.com/The-African-Queen-2006-DVD_W0QQitemZ360083828299QQihZ023QQcategoryZ617QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I don't know of any source that has (essentially) bootleg DVDs . My best suggestion is if you have them (or can get them) on VHS (or even better Laserdisc), copy them to DVD yourself.

I always wanted a couple of movies that were never released on DVD: "The Rescue" & "The Perfect Weapon". I was able to get them on laserdisc and copied them to DVD. I then resold them on and got my money back.

I still have a laserdisc player, so if you can find any of these movies in that format, let me know. I will be glad to copy.