This is one of the oldest US stamps and one of the first stamps that many collectors acquire when collecting the early US issues. Identification of this stamp is fairly easy. The bible on this issue is “The 3 cent Stamp of the United States 1851-1857 Issue” by Carroll Chase.
Scott #10 and #11 are imperforate copies. The difference is in color only. Scott #10 is orange brown and Scott #11 is dull red. Yes, there are varying shades on these issues, but those colors are the most common. Scott #10 has an orange appearance and due to it’s lighter color, it is brighter and more vibrant than #11, in my opinion. Scott #11 doesn’t show any orange. Scott #11 has a deeper reddish color, and in my opinion, a dull look to it.
Scott #10 and #11 are both Type I stamps. Type I has an outer frame line on all four sides. Type I shows the left and right outer frame lines being recut to varying degrees.
There is also Scott #10A and #11A. These are Type II stamps. Type II also shows some recutting of the inner frame line on the left and right sides. This is the inner frame line that runs from the upper rosette to the lower rosette.
In short, recutting was done to strengthen the frame lines. Because recutting is done by hand on various places on the printing plate, the line thickness varies very slightly. You probably need a 10x or higher magnifier to notice most of the recutting since because the lines are very thin. If a line is uniform in thickness, it is not recut. If you notice differences in thickness, then it is recut.
In 1857, the USPOD took the 1851 stamps and added gauge 15.5 perforations.
Scott #25 is Type I and Scott #25A is Type II. Both are rose colored stamps. If your perforated copy has an outer frame line on all four sides, it must be either #25 or #25A.
Scott #26 is Type III. It does not have an outer frame line at the top or bottom. It only has frame lines on the left and right sides.On Scott #26, the outer frame lines are continuous between stamps. On single stamps, the frame line continues into the perforation holes.
Scott #26A is Type IV. It too only has left and right outer frame lines. However, on #26A, the outer frame lines are not continuous between stamps. On single copies, the frame lines stop just short of the perforation hole. To summarize:
|10||I||Orange Brown||Imperf||Outer frame lines are recut. Inner frame lines are not recut|
|10A||II||Orange Brown||Imperf||Both outer and inner frame lines are recut|
|11||I||Dull Red||Imperf||Outer frame lines are recut. Inner frame lines are not recut|
|11A||II||Dull Red||Imperf||Both outer and inner frame lines are recut|
|25||I||Rose||15.5||Outer frame lines are recut. Inner frame lines are not recut|
|25A||II||Rose||15.5||Both outer and inner frame lines are recut|
|26||III||Dull Red||15.5||Frame line on left and right sides only and continuous|
|26A||IV||Dull Red||15.5||Frame line on left and right sides only and broken|