Fairly good condition just need a little lighting up, the joint pipe is very brown so that needs some more attention.
I use sdoc100 for degreasing and autosol for the heavily sooted parts. Not sure the joint pipe is visible once fitted, but is be the same and want them to be as clean as they can before fitting. Are you fitting yourself?
Autosol will clean it up but you will need an abrasive brush but not to abrasive that it scratches the ally, I use the washing up sponge with green backing, plus a lot off elbow grease.
You could go a totally different way & forget cleaning it & send it too Ultra high performance ceramic exhaust coatings who'll blast it clean & then add a plasma ceramic heatshield material. Which will look as good as new each time you clean the bike. Rather than needing every year or so too remove the exhaust.
