Posted By:
BenHi Rob,
I got your email and thought that it might be best to post my answer here. The T213 set is actually made up of three distinct issues, which is why you will see them commonly referred to as t213-1, t213-2, t213-3. You can distinguish between the three by their back advertisements.
T213-1: "Coupon" (mild) Cigarettes
T213-2: mild and sweet, Coupon cigarettes, 20 for 5 cents
T213-3: Coupon cigarettes, 16 for 10 cents, mild and sweet
While there is consensus that t213-2 is the most common of the three, I have heard mixed messages about the relative rarity of the other two. My personal belief is that type 3's are the rarest. Also, type 3's are the only series that contains the overprints, which is just a little black bar across the factory/district #'s on the bottom of the back.