The gunners/bombardiers compartiment of the TBM-3 should be a little more dressed up, here's a suggestion:

As you can see I have drawn a ammunition box with the bullet chain leading to the machine gun.
The cylinders above the mg are searchflares with the including flareshute (leads out the right side of the fuselage)
On the right side you see a parachute and a device to switch on/off the guncamera.
Furthermore you can think of stowing a liferaft, emergency signal-gun + flares, extra munition boxes etc.
It would flower the compartiment up abit
