Sid Greene Inking Barry Smith (or not)
Nick Fury, Agent of Shield #12 was dated March 1969 and marked Barry Smith's fifth interior-artwork assignment for Marvel Comics (and he also received a co-plotting credit for the story). Sid Greene, who had done such a nice job inking some Gil Kane Green Lantern and Atom stories for DC, was assigned to ink the Shield story and completed the job. Just one problem: Mr. Smith detested those inks on his pencils.
The above original page of original artwork from the issue was up for bid on ebay recently. The seller pointed out that most of the inking is on vellum overlay because Barry Smith re-did it himself over the span of one weekend rather than let the Smith/Greene collaboration see print. If I had bought this artwork I probably could not have resisted peeling back the overlay to peer at the secrets that were hidden underneath.