As Rwwear stated, the woofers are Advents - the type with the masonite ring mounted over the metal basket. It is a very good woofer, reasonably long-throw (for it's era) with an oversize diameter foam surround.
If the foam surrounds are shot (which they must be) re-foam them - do not buy "replacement" drivers.
If the foam surrounds are shot (which they must be) re-foam them - do not buy "replacement" drivers.