Here's two covers Jim Steranko did for the Marvel Comics Index Series, both published in 1979. At the bottom is an attempt two stitch together the two scans of the Captain American wraparound cover.
Jim Steranko's masterful covers of Nick Fury, Agent of S.H.I.E.L.D. I can't imagine what it was like being a kid in 1968 and finding stuff like this on the newsstand every month.
Nick Fury, Agent of S.H.I.E.L.D. #1, June 1968.
Nick Fury, Agent of S.H.I.E.L.D. #2, July 1968.
Nick Fury, Agent of S.H.I.E.L.D. #3, August 1968.
Nick Fury, Agent of S.H.I.E.L.D. #4, September 1968.
Nick Fury, Agent of S.H.I.E.L.D. #5, October 1968.
Nick Fury, Agent of S.H.I.E.L.D. #6, November 1968.
Nick Fury, Agent of S.H.I.E.L.D. #7, December 1968.
Here is a scan of the original art by Jim Steranko for Eerie #25, January 1970 and a scan of the published magazine. This was Steranko's only cover for Warren Publishing.