As georgehifi says the KEF T33 is a great tweeter. Once cleaned up and new ferrofluid applied it will be as good as new. It is a straightforward process. There are several online videos for the process and plenty of discussions on Audiokarma. The ferrofluid is readily available from Parts Express.
As for the surrounds and donuts, it depends on which version 104/2 you have. The earlier version had rubber surrounds and foam donuts, so only the donuts may need replacing. The later version, which can be bi-amped, had foam surrounds and foam donuts, so both may have to be replaced. You can visually see the bottom woofer through the front port and check the condition of the donuts and surrounds.
As for the surrounds and donuts, it depends on which version 104/2 you have. The earlier version had rubber surrounds and foam donuts, so only the donuts may need replacing. The later version, which can be bi-amped, had foam surrounds and foam donuts, so both may have to be replaced. You can visually see the bottom woofer through the front port and check the condition of the donuts and surrounds.