saucermen

[Mullins, Bill]

OED has 1967 for "saucermen" (under saucer, n.).

This comic book

http://www.cufon.org/comics/1950/SpaceWestern40.htm

has a story titled "Spurs Jackson vs. the Saucer-Men"
_Space Western Comics_ No.40,  Charlton Publications, September/October
1952

The gallery of comic book covers from which it comes
http://cufon.org/comics/ComicsGal1947-9.htm
has several pictures of "flying saucers" that predate June 1947, but
do not use the term "flying saucer" (at least on the front covers shown)
to describe them.