This question comes up very, very often. So often, as a matter of fact, that a community member wrote this article.
http://stampsmarter.com/learning/ID...arities.htmlAdditional information on how to ID rotary press printed stamps is also here
http://www.stampsmarter.com/learnin...methods.htmlBetween these two webpages, you should be able to learn how to ID US W/F printing varieties and how to make a template.
Please note that even if you had 10,000 of these stamps they printed billions of them. These stamps are as common as rocks. If you went into your backyard and grabbed 1000 rocks, what are the odds that one of them might be a diamond? This is why we recommend the best perspective is to always assume that you have the most common varieties. Collectors having sorted through millions and millions of these stamps over the decades and only a handful have been found.
As a last suggestion when folks are convinced that they have found a rarity, we typically tell them to go ahead and spend the money sending their stamp(s) in for a certification.
Don