You're absolutely right, the 42/43 drm should be a -1 instead of a +1.
Can't believe nobody's picked up on that before...including us. Doh. Consider that part of the official errata until we update it (haven't had any in months now.)
OK, now I'm confused. You guys keep talking about the modifier 42/43. But All I see on the chart is the +1 modifier for 41/42 ?