Cut the horizontal profile. The fretboard is going to sit in a slight cavity in the body. Most of the sides will be gone when the vertical profile is cut but right now they're acting as buffers in case something slips . Here's how it went down.
Put the fretboard template where it will go, outlined and carved it out with a chisel, square ruler and a razor. Didn't have a scraper small enough so I actually used the ruler edge. I used the ruler to plunge into the carve to be my gauge for the depth and carved to that point to make sure i didn't go too far.
When I got the right angle I just took my time to get the edges right for the fit and used the ruler edge to clean and level what was left.