Thanks. This represents the doctrine in place when I ran my FDC. Instead of two charts, one primary and the other to check, we had one chart and "Freddie" FADAC. Which was "primary" and which was the "check" was always an interesting question. We observed that in MOST cases, the "charts and darts" method was usually faster in obtaining initial firing data, but on subsequent corrections, which were usually a lateral shift, the FADAC was faster. Had to do with how it calculated the data in each case.
That FADAC is scratch built, so I'm betting you can do the interior on yours!