Our 16 tourings block was cast 11/16/15 the body tag says 12/15 so I guess the birthday cake can wait till next month!
My 16 coupelet engine was assembled Nov 18th 1915. Not sure about the assembly date.
My touring has cast date11/23/15 so by your dates mine should have rolled out 12/22/15. I bought it as a 15 before I knew anything.