age related
dont discount the gear's sonic value until you have heard it,age mean's very little especially with speaker's,ofcourse the issue of rotted surround's & dried out part's in the xover's need's to be addessed but if all is well then give it a shot & see.
i have a 4 year old pair of klipschorn's & a 20 year old pair of mcintosh speaker's that still work great to this day.
i personally do not think that speaker's have evolved that much in the last 20 year's & in most high end big $ cases they have went backward's giving away any bass response in favor of midrange