I did not sand these but used a polishing wheel, and polishing paste on cloth wheels, to achieve this result. Took me about ten minutes per hub...
Add a bit of sunshine and Bob's your uncle...
If you are just going to sand, start with #1000 wet and dry (used wet) and then finer and finer until you are happy with the result. This takes more than ten minutes per hub. Then, make sure to clean off and protect with wax.