There are many varieties of doubled dies other than the major ones you see in books such as the Red Book. You need to learn what to look for to identify a doubled die from other types of doubling and common coins. Once you learn what to look for, you will be able to recognize even the more minor doubled dies. Check out this website: http://www.lincolncentsonline.com/index.html look through the "other doubling" page along with the doubled die page, then study the error guide. It may surprise you what is out there if you know what to look for! Hope this helps!
There are many, many, many varieties rarer than the Big One. There are tens of thousands of 55 DDO's in the wild - it isn't valuable because it is rare. It is valuable because it is significant and popular, and the popularity (as compared to the supply) has driven the price up. If there are only 3 examples of a variety known, it is incredibly rare - but if there are only 2 people that want it, there is far more than enough supply to meet the demand. That's what a lot of people don't understand about key dates. Many key dates have a significant number of examples known, and they trade very often (just try looking for a 09-S VDB Lincoln, or a 16D Mercury - I'll bet you'll find hundreds of them for sale). But, compared to the demand, the supply is inadequate. The same is true for the 55 DDO.
Well I personally don't collect Lincoln's , I did however find five 2-o-ll+v NGC graded them as MS-64 red and after cost I ended up with $750.00 @ pop! And they sold faster then any other coin I ever listed on e bay.[/QUOTE]