I can't tell you the "name" of the theme as I want to use it as a contest (guess the theme) when I hit 500 posts.
Without giving too much away I'm looking for any 1/2 dollar size coin that circulated in a given country from 1937 to 1945. Here are the harder coins I'm having a tough time with:
1. Costa Rica 1937 1 Colon (I'd also settle for a 1935)
2. Cuba I think the closest I can get is a 40 Centavo from 1915-1920 or 20 Centavo (I know closer to a quarter in size but I'll make a concession)
3. Haiti 1908 50 Centimes - again not in my exact date range but they didn't make a lot of coins so I have to assume it circulated during this time.
These plus the Luxembourg franc mentioned earlier have been my problem children.Just an update. I picked up two more coins so my list is slowly going down

Edited by Ken_3567
03/30/2008 7:09 pm