If they hit 60% of the target production rate by early December, that's two to three week's worth of production. Basically, you are saying that they don't resolve the initial production problems until early December. That's quite pessimistic.
Another point of reference... the Model X ramp, deliveries per month:
6, 4, 5, 199, 270, 270, 1860, 795, 1600, 2145.
This is a much more difficult vehicle to ramp up production... and after the 1,860, they were still sorting out door seals and every vehicle had to have door seals replaced that also held up deliveries... and remember, the target production rate was about 50% of 2,500/week, or 1,250/week... but the actual deliveries is based on the order mix (the S and the X share the general assembly line).
The target for Model 3 is 5,000/week for the initial production line, or 4 times the rate of the Model X production. We likely are already past the first six months of Model X production equivalent.