I advised on RAFCommands forum to check the CWGC at least for 12 months or so after the dates your interested in. You will find some of the mens names there and suggestions for others.
http://www.rafcommands.com/forum/showthread.php?t=8909
With a name like Dvorjetz , you can be fairly happy that he is
Sgt G A DVORJETZ died 16/07/1941
I gave you a number of likely names from CWGC, all of whom died with 18 Squadron in 1941, you could at least suggest them in your list as likely candidates.