TW3,
Both this thread and the deleted one are about facets of this same stamp and should be together.
Moving on, I am going to repeat my post of 3 days ago...
Quote:
Based on your title .... have you eliminated the 279B family?
Before you get to shade considerations, what research/homework have you done and what are your conclusions differentiating Type III vs Type IV?
More generally, if you are interested in figuring out a "value" for your collections, 5% of the stamps will have 95% of the value, and more likely 2% will have 98% of the value. It will save you a lot of time to have an experienced collector/dealer survey the collection and give you an idea of what can be evaluated "in bulk" and what deserves individual attention and study.