Ive done a similar repair to a 550 100%C mast. It had damage to both upper n lower sections of ferrule. Basically, superglue cracked area of sleeve together. Use hoseclamps to secure once ferrule is put together. Leave it to set. Remove hoseclamps.
Then use carbon weave around the sleeved section. Make sure wraps go further past the cracked area. Use a few wraps to build it up. Finish with a wrap of glass for abrasion resistance n strength.
For the inner spigot section if cracked. I used a section of carbon mast the correct diameter. Epoxy that inside the spigot. Fair around the cracked spigot area with epoxy, sand to fit upper/sleeve. Go sail once cured. Happy days.