I was just about to write the same thing. Brass is too soft. You didn't say which lathe you have. The compound swivel lock pins for the 6" are M6-309. For the later 10" and all 12" they are 10-309. In Downloads is a drawing of the 10-309 that I made from one of mine about six years ago. I haven't checked recently but last time that I did, they were still available from Clausing, so they won't release the Atlas drawings.
Note that on mine, I measured the angle of the bevel as 60 degrees (or 30 degrees for the included angle. And the diameter is 0.310". Note also on the sketch the radius cut on the bottom of the bevel.