1/800 Mark 7 life boat containers

[sctbrd]

I working on a 1/800 ARII Theodore Roosevelt (ca. 1993), and want to add life rafts to the railings.
Due to the large number (>200), I would prefer to make my own, instead of buying 3d printed.

Is there a technique/trick to get a relatively proper container shape besides cutting each one and sanding the ends?
I dont necessarily need the ribs, especially at this size, but want to get the pod shape fairly close.