Filament spool bowl cover

Found a spool storage but cover was designed badly and didn't allow to stack bowls. So I designed a flat version but then problem was a size. I am using Prusa i3mk3 where bed size is 250mm x 210mm. Bowl cover diameter is 235mm. I have to cut it in half and create a simple joint.
I will add later a desiccant inside the bowl for longer storage. Bowl from LIDL and branded ernesto.
Printing upper cover no need for support but lower one needs build plate support.