[cctalk] Date of IBM 1/2" tape from factory number

Dear list denizens, I've got a mental itch that needs to be scratched. Before me sits a yellow 3-hole reel of IBM 556 bpi 1/2" tape. Fortunately, the leader is intact and carries the number H241032488. Does this perchance give any clue as to when the tape was manufactured? I know that IBM still carried 556-tested tape in their catalog as late as 1966. Any clues? Thanks, --Chuck