Interesting findings about the LSC and SBC. It would be definitely usefull to have them in the sim. 16 40lb bombs would be just like the AO-10 in Il-2.
WWII allied fuses are quite simple, mostly mechanical. Ever ready fuses are working like a nail. If you push them on one side it will put presure on the detonator charge which leads to a chain reaction known as explosion of the bomb.
The more common mechanical fuses are armed by time with a spinner which is spinned by the airflow. When the spinner reaches its final position the bomb become armed an will expolde on contact. You can put a timer mechanism in the above mentiond constuction, which will count down from the moment of inpact the a pin will put presure on the detonator charge.
Most of (if not any) the fuses have a safety pin which blocks all above mentioned actions. Usually it is removed by the falling of the bomb, Imagine a pin in a slot (in the fuse) which is tied to the releasing mechanism on the plane.
Here is a schematic of a very primitive mechanical fuse for aerial bombs
