Hello friends

I rescued these two cacti from my father's home after he passed away. He had them for years and they've always looked like they are on their last legs, but they refuse to give up, and keep on growing. Is there anything I can do to give them a new lease of life? I'm particularly concerned about the tall one that is all brown and split at the bottom. I would love to save them, I feel like they deserve it!

Thanks very much in advance for any advice you can offer.