Just her lines? I mean, nothing historical or someone brought a pumpkin aboard the ship and celebrated with it something like that?
Her sailors turned to farming after the war, or was it shortly before the surrender? Well, she was way too damaged to be sea-worthy after Ten-Go. Pumpkins, especially of the kabocha variant, were one of the products farmed by the sailors. So, Suzutsuki is perhaps the only duck who is self-sufficient.
Just her lines? I mean, nothing historical or someone brought a pumpkin aboard the ship and celebrated with it something like that?
Shebadotfr essentially has the right of it. Late in the war, her crew turned to fishing and farming ashore to supplement inadequate supplies. Nobody had enough anywhere in Japan in those days. Pumpkins were a large portion of what they grew.