59BJ- '59 bridge or jazz bridge?

[7turns]

I've got a bridge pickup to try that I was told was a jazz bridge. The code on the sticker the back is 59BJ. Which reminded me that I have another SD 59 I got off ebay that was told to me to be a neck position p/u. It has 59NJ on the sticker on the back. So are these really older 59's or jazz pickups?
thanks,
matt