Reworked from story in Amazing Adult Fantasy (Marvel, 1961 series) #12 [Melvin and the Martian!].
Story was originally scheduled for The Silver Surfer (Marvel, 1968 series) #8. It was originally written as 10 pages but reduced to 6 for publication here. Page #8 (of 10) was published in Marvelmania Magazine #1 1970 and page 7 can be seen here: http://www.comicartfans.com/gallerypiece.asp?piece=935801.