At Epping Forest Horology Club we tend to either be 'Autosol Men' or 'T-Cut People'…both have their adherents who prefer one or the other for various reason. Personally, i'm a T-Cut fancier, but not by much!
Most members of the club who are serious about polishing brass (and there are some who are VERY serious!) stop with the abrasive papers at around 3000 and graduate to 'microfinishing film' which are made both by 3M and also by some Swiss makers notably Graessner. These films are described in microns unlike abrasive paper.
We mostly aquire our films from the large horological supply houses, Walsh or Cousins…see here for Cousins finishing films……..
https://www.cousinsuk.com/search?SearchTerm=finishing+film
A word of caution if you are going to get involved with finishing film,……..it's not as easy as it looks and there are several pitfalls for the unwary. Contamination quickly becomes an issue…it's highly irritating to get a superb finish on a piece and suddenly find that the surface has efects due to microscopic contaminants. For this reason its quite easy to become an obbsessive before you realise it and you are suddenly looking at a forensic white overalls and turning the shower room into a laboratory………You have been warned! Then there is the issue of keeping the films stored in utter cleanliness…….
Unless you are aiming at the very finest work it might be a plan to polish to 3000 or so using a sheet of plate glass to hold the paper to, and then use Liberon 0000 wire wool (which is super nice and fine to use) and then a CLEAN polishing mop in the lathe with just a touch of T-cut…..