I don't know, CB. Looks like a 100lb GP bomb to me.
British and American Bombs of WWII
1. RAF 22,000 lb Grand Slam, the largest high-explosive bomb ever made
2. RAF 12,000 lb Tallboy, used for breaking through the concrete roofs of U-boat pens
3. USAAF 4000 lb Blockbuster
4. USAAF 2000 lb Blockbuster
5. USAAF 1000 lb armor-piercing bomb
6. USAAF 500 lb standard demolition bomb
7. USAAF 100 lb bomb with nose fuse;