Between Nov 1999 and Jan 2000.CDT57XX
The N6xxxxx range ran from 1979 to 1980.N6684xx
1909.It's a pre model 10, serial number:
145xxx
That SN was used on both 5 and 6 shot models but at different years.The s/n is 86xxx
.38 Military & Police Model of 1905, 4th Change.the # on the butt and under the barrel match 297xxx