The bombardier did not have the ability to select an individual station using the panel shown. He would open doors, set Arm/Safe switch to Arm, and switch the Bomb Bay switch to On. Then with each bomb release pulse, the bomb from the lowest numbered station that was loaded would drop. The sequence was left to right and then up the rack. For example, if 1000 pounders where loaded on stations 1 and 2, and 500 pounders where loaded on stations 3 and 4, there was no way of dropping the 500 pounders before dropping the 2 1000 pounders and clearing the lower stations. Even if station 1 had a 1000 pounder and station 2 had a 500 pounder, you could not bypass station 1 and drop the 500 pounder at station 2 first. You could not change the order once the bombs where loaded and there where physical constraints on which size bomb could fit at each station. Aces High has done away with all that for the sake of playability. By selecting the size bomb you want to drop in flight, you are essentially changing the order the bombs where loaded on the racks before you took off. How often a bomber took a mix of bombs in real life, I dont know. But they would have to know what size bomb was required for each target and the order the targets would be attacked to know how to load the bomb bay munitions match mission requirements.
As far as the Lancaster, with their long bomb bays, they may have had more flexibility in selecting which bomb to drop.
Good find on the 5 rockets on the B-25. Probably worth another wish.
But just to stay on topic, they should display the bomb size selected (with the number remaining) at the bombardiers postion.