This is one of the two author's copies of the third revise for Signature O in the Delaware Art Museum library. This lacks the sheet with pages 195 and 206, the other is a complete proof. Two other (uncorrected) copies of this revise are also in the library. This proof has author revisions at pages 194 and 201, and some printer's markings for improving the text spacing.
Besides this third revise proof copy, the Delaware Art Museum library has
the following proof copies of Signature O: the