The art in that supposed prototype page doesn't match the supposed cover above it, and doesn't really matche the art style popular in comics at the time as I recall (looking at the 1991 copyright date on that cover), though the cover seems more in line with late 80's, early 90's comics. For all I know the cover could be legit, but the page below it definitely isn't. It looks more like an anime styled webcomic to me. I'd say it's a poorly crafted hoax.