"May 1951" doesn't seem like it can be the correct issue date. I say that because #1 is dated simply as "1950", and issue #3 is POSITIVELY dated (by its own indicia) as "May-June 1951" -- so it hardly seems likely that a first issue was dated sometime in 1950, followed by one dated as May 1951, followed by one dated as May-June 1951. Since "May-June" indicates a (intended) bi-monthly frequency, it seems more likely that issue #2 would have been dated "Mar-Apr 1951", and issue #1 "Jan-Feb 1951", although of course we would have expected any of those issues to actually be ON the newsstands 2 months (possibly even 3) earlier than the first month of record of publication. That would mean issue #1 first went on sale in 1950 (probably in November, but possibly even October). And indeed, #2's indicia shows a 1950 copyright date, indicating that it was sent to the printer in 1950, not 1951.
Link to the book:
Amazing Adventures 2