Japanese Lantern concrete mold

For some strange reason, I've decided to create my first cement casting mold for a rather complex object.
Could I have chosen something simpler? Yes.
Could I have tested it myself? I should have...
But what you see is what you get.

A three-part Japanese lamp: the base and roof are simple, made with circular molds divided in two and held together with screws.

The central mold consists of an outer casing, which can be printed without supports, and an inner mold made up of a cylinder and four round "corners" that slide into the cylinder and middle joins between corners. Some supports may be needed for the internal corner mold and middel joints. External mold, middle joints  and internal corner, must be printed x4. 

To assemble the mold, first assemble the inner mold, and then fit the outer sides into it. Wrap it with string or rubber bands. Make sure to coat the surfaces with petroleum jelly or vegetable oil and fill any joints and gaps so the cement doesn't seep in.

To disassemble, untie and remove the central mold. Then the middle joins may be pushed and the corners of the central mold will detach and can then be removed.

Top mold and base mold are much easier, screws and nut are included to hold everything together, be sure tu print as many as you need.

v2. Update
@mjk_boron notice that the round corners may have difficult to unmold blocking each other to move inwards, so now a middle joint part is included, that may be pushed after extract the middle cylinder.  I Must thanks the feedback.

v3. Update, an user make me notice a problem in the base that prevent to unmold, now is a 3 pieced mold to avoid that problem