Chuck, that sounds quite plausible. On P.25 Ferris gives some figures from which he deduces that at Eddystone the total lead time from the first machining operation to a finished receiver ready for assembly in a rifle was 31 days. In other words, if from Day X no new receivers were started, the numbers in progress would have been sufficient for another month of full production. With production running down, this number would have lasted even longer.
As the end of the war was foreseeable, and no new contracts had been issued, one imagines that the factories would have tried to avoid being caught with masses of part-finished components after the contracts ran out. Contracts may have provided for compensation for completed rifles, or completed parts, but hardly for raw material stocks (which could be used for other purposes) or part-finished components, which would be scrap.
This ties in with your thesis - that new production of components was run down in anticipation well before the contracts were terminated on 9th Nov. 1918, and the factories were already assembling rifles largely from components completed and stockpiled some time before. It would be interesting to see the source info, if you can find it.
Patrick