It would appear that the thread chart is incorrect: actually totally messed up. You would have an Imperial lead screw, as indicated by the thread indicator. The large side gear should just function as an idler, as shown in post #26 and it could be either the 120 tooth or the 127. The other gear isn't used for Imperial threading only as a transposing gear for metric threads. In that regard, the gear placement charts are wrong.
It also appears that your gear set in wrong as listed. I would guess that the actual number of teeth on the gears in positions 1-6 are the numbers listed in row C.
Looking at your chart and your results, I would expect that column 4 is actually 5-1/2, 11, 22, 44, and 88 and column 4 is 5-3/4, 11-1/2, 23, 46, and 92. Your C5 test shows 11-1/2 threads for 12 threads on the pitch gage which would be 23 threads for 24 on the gage.
You might try position 3. The need for the threads listed in position 3 are rather obscure and that gear may have been dropped and someone didn't properly update the threading chart. If I am correct, the correct numbers for position 3 would be 5, 10, 20, 40, and 80.