TBH, all of it seems unlikely on a tank, even when the crew is supposed to be stowing the vehicle. Especially the machine-gun ammo boxes: in vehicles, MG ammo was stowed in canvas bags with a metal lid, not belt boxes:

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These attached to the machine-gun mounting in a clever way so that when reloading, the new bag pushed the empty one to the side where it would then collect spent casings and belt lengths:

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(Though in this photo the feed tab on the belt hangs next to the empty bag, of course.)

The stick grenades would also be dubious. They take up a lot of room, and AFAIK the grenades issued for vehicles were mostly or exclusively egg grenades:

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Note there that the ring is not for pulling  It's there to allow carrying the grenade more easily. The detonator is the knob on the right: unscrew that, sharply pull it out to activate the fuze and then throw before the delay is up (with a yellow knob, as here, that's 7.5 seconds).