Dating a reel not a person

[chrisott]

I am about to buy a Penn international 20. I believe it is 1st gen. I was wanting to know the year of Manufacturing. I know on some internationals it's the last 2 numbers of the serial number but this number (NB5009) doesn't fit that criteria. Any help is much appreciated. Thank you

[Penn]

That style serial number puts date range late 60's early 70's.

tony