How to ID 60T wrappers by Series
 

Hi Gang:

I see on the PSA SMR Price Guide they list 1960 Topps baseball 5 cent wrappers by series 1 thru 7.

How can one ID which series a wrapper or an unopened pack comes from?

Is it by the "offers" on the back like you can send away for the album, or the iron on's etc.?

Any guidance on how to figure out what series is which wrapper would be greatly appreciated.