Sam- Brass is so maligned compared to silver these days. Millions of frames are on the road using only brass for everything and haven't resulted in thousands of failures. Brass is far more forgiving with fit up and gaps, with less then ideal cleanliness and vastly cheaper to practice with. One of the challenges with canti bosses is their set up. Depending on rim widths, pad thickness, canti design and how this all results in a boss base/stay (blade) relationship can be hard to get right. Spend some time figuring out the boss location and how to hold the bosses during set up then also brazing.

Attend the brazing clinic as you are also getting the bosses prepped. Plan on a few brazing sessions before doing the frame work. Andy