Lastspikemike
Just a reminder to other readers trying to use all of this information: 7/16" is basically half an inch. That's a big gap.
Before we all get lathered up about a 7/16" gap, let's recall that the 7/16" measurement was a guesstimate between Pruitt's indication that the dimension from the center of the turntable to the doors is 11 15/16".
Kevin indicated that the 90 foot turntable bridge is about 13" long, or 6 1/2" to center. That should give you about 5 1/2" of track between the turntable and the roundhouse.
Turns out, the exact distance was 5 1/16", or 7/16" difference. Not bad for a guesstimate. After all, JDawg's original estimate was 12". That's the beauty of the formula - - exactness.
Lastspikemike
Use the same techniques to cut and fit roundhouse connecting track as you would for any track fitting. You don't need to know how long the track needed is, just use a piece long enough to cut to fit. You could cut all the pieces from just one instance. They all should be exactly the same but only if you're very accurate in your placement of the roundhouse and turntable. Mind you, using lengths of connecting track all cut exactly the same from the one example should orient your roundhouse to the turntable very accurately.
And that is why the forumula is so useful. It tells you the exact distance between the edge of the pit on the turntable and the front floor of the stalls.
In fact, once the formula provides the exact distance, that measurement can be used to perfectly align the roundhouse with the turntable.
Each and every connecting track will be the exact same distance whether the outermost stall or the middle stall or any other stall in between.
The shortcoming of your two-line theory is that it fails to identify that exact distance. It only tells you the distance from the centerpoint of the turntable to the round stall floor. You still need to know the radius of the pit to determine the exact length of the connecting track - - every connecting track.