I already voted so I won't comment the design here.
Definitely don't use frames. I don't like CSS either, but that's OK for me. I don't know what layers are, but if I don't need to do something like enabling/disabling htem, it's OK to use that.
Old netscape: Maybe redirect old browsers towards the old web saying it is not up to date, but there may still be interesting links there? Also beware some people on Apolyton use Opera. I don't know what Opera supports, but if you test for the browser in the pages, it's better not to kick them out if they can read the pages.
Images: Well, presented the way you do, we have little choice. How many images would you need/wnat, and what kind? We can probably get a few from scenario designs, like reproductions of paintings or mosaics, which should be quality and free, considering the author of the mosaic is usually dead since a few centuries. I think a portrait of Alexander, and I must have a mosaic of Basil II of Constantinople somewhere. They are not as impressive as photographs of sculptures, but they should be cool. Paintings would be even better.