IMO your best bet is to replace the defective woofer with an original if you can find one. I’d call around to a few speaker shops and see what they recommend. GR Research, Madisound, Meniscus, etc.
Being that those are a two way design, the woofer plays a huge role in vocals and the critical midrange. Replacing one woofer would function, but would not likely yield satisfactory results. Replacing both woofers would also function, and both speakers would at least be the same, but would also be sort of a crap shoot as to whether they would sound good. You might find some mods online that use replacement woofers for those speakers, where someone did some due diligence and worked out details that result in a nice sounding pair of speakers.
You might also find a whole DIY kit where you could salvage the cabinets, and replace all the drivers and crossover.
