Info you're looking for is in the sticky post right above this one. Yours was made in 1971.

http://www.savageshooters.com/showth...-Letter-Prefix

The SP stamp is the proof stamp (Savage Proof). The 19 stamp is likely the assembler's number. No clue on the other stamp, but it wouldn't have anything to do with dating the rifle as starting in 1968 the serial number was used for that.