Lieber pencils and possible Milgrom inks per Nick Caputo, June 2012. Romita alterations per original art as seen on comic art fans:
http://www.comicartfans.com/GalleryPiece.asp?Piece=200376&GSub=73519
Slight crossover with Aquaman #56 as confirmed in the introduction to Marvel Masterworks: The Sub-Mariner Volume 8.
Sub-Mariner appears next in Giant-Size Defenders #3.
He becomes a co-feature with Doctor Doom in the series Super-Villain Team-Up, which picks up the Atlantis sub-plot.
Editorial afterword and final closing notes from Roy Thomas and letters of comment from Ed Heyne; Brian Schuck; Peter Cucich; and Randall Freeman. The single illustration is a panel detail reprinted from page one of issue #70. The Marvel Value Stamp #100 (the final one in Series A) is revealed to be Galactus.