Finally, after much searching, help was at hand. In fact the printer IS supported in OS X 10.2, and this link explains how.
It is very simple to do, and it all seems to work fine, and I guess it might work for other "unsupported" printers too. Thanks to cblue for making this info available, and no thanks to Apple and Epson for keeping it a secret.
[robg adds: The referenced URL covers using the Option key to access the "hidden" menu in the Advanced section of the Print Center. We have run a number of hints concerning this hidden panel, though none seem to address this general subject of using it to enable unsupported printers.]

