Nice work all round. I think I'd be tempted to leave off all small parts, such as that ring sight, until last. Sod's Law says they'll go 'ping' whilst handling and finishing off otherwise.
The type 99 250kg Bomb should be in a Grey green similar to the aircraft colour with a green Nose/Tip and struts on the rear of the Bomb, and thin red strip running the length of the bomb on either side nose to tail.
Pearl harbor vals did not carry the 60kg bombs under the wings.