It was only recently that I started painting brass models. Somewhere in this thread (or perhaps elsewhere) that Bob Turner recommended a light bead blasting and then straight to the paint booth (after blowing off the model with compressed air). I tried this recently on a couple of Max Gray cars and had very good results.
I then tried it on the chassis of a CLW diesel. That worked well
except...

...that I turned the pressure up a bit to clean the rails of the chassis well and in the process badly bowed in and otherwise dented up the fuel tank. The solder lines in the above photo mark where I cut three strips out of the stretched tank to bring it back to near flat. The rest I had to fill.
It was a careless error, but I will say that there is a fine line between just enough pressure to get the beads to flow at all and too much pressure. For my setup (Harbor Freight booth), it takes between 30 and 40 PSI to get a good flow of beads. I had the pressure around 60 psi when the tank got beat up. Of course, being what it is (a big unbraced thin flat brass sheet), the tank is a soft target.
Jim