You re right!
I'm working on it too and I hope I will able to replace the whole central superstructure about the end of the year.
The stack. Almost completed, I only need to add some small details.
The ladders will be separate and added in the assembly.
There will be also a door in it at the other side, as on the original ship
Central superstructrure with stack and main vent holes.
The speaker will be below them, so the engine sound will come out from the stack and the main vent.
Also You can see the fire control tower is half a deck rised and now have height of two full decks.
This is needed to assure near surface guided fire at all stern angles.
Already sent to be printed.
The Main and auxiliary vents. The huge hole of the main vent will be covered with grate,
which I ordered in photoetched variant, to be more realistic at this scale (1.5mm holes, 0.2mm rods thickness).
Still need a little more detailisation.