IIRC the field mod to the H model of the B-25 was the removal of the 75mm and installing an additional 4 .50 cal's in the nose for a total of eight, plus the four cheek guns and the ability to lock the top turret to fire forward for a grand total of 14 forward firing .50's. I belive Gen Kenny had a bunch of his B-25's modified in this manner due to the slow rate of fire of the 75mm. I seem to recall reading that in a book somewhere, then again I could be wrong.
If we get the B-25 though we need para frags. Would be easy to do. Take the already modeled 5" artillery shell and put the already modeled troop chute on it. Must be above 800ft to drop them, just like troops. B-25 could carry a butt load of those things too. Could be fun.