Hallo Jon,
I have a Nomad and cut symbols and engravings into brass regularly.
My current go-to for engraving is this v-shaped ball end mill:
I cut either 0.1mm or 0.2mm with a 0.05mm depth-of-cut, usually slowly at around 200mm/min, and get really nice results with quite a bit of detail. This fellow lasts a reasonable amount of time, too.
For cutting the brass itself (this depends on which brass you have) a single flute 3.175mm can cut 0.2mm-0.25mm per pass pretty well at around 200-250mm/min.
The type of brass matters… CZ121 is nice and soft and cuts well with these. Harder brass will mean you have to pull back a little on the feed rates, in my experience.