Hello Steve,
Yes 45, and only one "FW" out of 500 or so Cornwell's listed on the NARA site.
Many on return to the US I think had to re-enlist as they served in UK or other Forces and had continued to use that "ID" (?) but on returning to the US the paperwork caught up I expect. Don't forget many had broken US Law when they came to serve in British/Commonwealth Forces, and some I expect had not used their true names either.
There was one I found in Canada,
http://www.veterans.gc.ca/eng/collec...Detail/1085012
But it looks like he was killed while in Bomber Command and the initials are not 100%.
It does look as if your man survived the war .
all for now,
Alex