What I thought was a simple M1917 Eddystone question.

[Kywoodwrkr]

I have posted a question dealing with the manufacture date of M1917 Eddystones with a serial number greater than the limit of 1355000, on www.m1903.com website, on multiple forums with no response. How long after the serial number of 1355000 did they(Eddystone) make the M1917?
Anybody here have any idea? Appreciate any input. Thanks.
DaveP