[RICHARD]

How to tell the difference of Scott 331 and Scott 374 when its on cover or used with date on it. Scott 331 was first used Dec  2 1908. Scott 374 was first used Nov 23 1910. Now you have a time line. So any dates before November 23 1910 are Scott  331 types. You can use this with other Scott numbers as well as long as you Know the Earliest date used  and there is a date on them and there are only two types with the same perfs. That will narrow it down for used stamps with dates. Happy hunting. So what is the Scott number of this stamp? To rule out Scott 357 Bluish paper, if it has a yellow tinge to the ink and the paper looks like its white and not light gray. Then its Scott 331 or 374.