Well guys I don't know if combo's are worth $$$ or not, but I sure do love mine either way. After five months of work, which was an wonderful learning experience for me, I'm finally done with the restoration of my 1951 Zenith Combo. All three components were completely dead when I got it and now they all work great. I love the 19" round tube, its great for watching old movies on.
By the way, one of my favorite things to watch on my antique tv's are old industrial and educational movies from the Prelinger archives. The picture below from my Zenith is from the film "The Story of Television". They have quite a few vintage radio and tv related films at this site. You can download over 1000 of these movies for free. If you download the VCD (MPG) versions you can use your CD-R burner on your computer to burn them to a VDC video disk and play them on your vintage TV's through your DVD player. Here is a link to the site:
http://www.archive.org/movies/prelinger.php