The number you listed for the 10-5 is the assembly number, which is arbitrary and basically meaningless. The serial number of a Model 10 is found on the bottom of the grip frame. It will be a 6-digit number preceded by a "C" or a "D".
The Model 19 is 1976 production.
"Smokey, this is not 'Nam. This is bowling. There are rules... MARK IT ZERO!!" - Walter Sobchak