Rick
The dates I used from the sheet are warehouse acceptance dates. I had mine lettered and it was accepted in December 1910 and shipped in August 1911. The other date I have is just the warehouse acceptance date. From old posts here no doubt on someone's rifle.
Wouldn't the A suffix define the 1909's from the 1903's in JTC's books?
Did some arithmetic, subtracted the first recorded 1909 from the last 1903 recorded = about 530 units between the two.
First to last recorded 1909 = 11071 units
Your 3000 +/- from 1912 thru 1915.
So maybe 16,000 give or take.