Sarinda is a WWII 72 foot HDML (Harbour Defence Motor Launch ML1392) that saw action as a Channel Marker at Gold Beach for the D-Day landings in Normandy. In later years she served many other rolls. In the 80's she was converted as a motor yacht but soon fell into disrepair due, IMHO, to the conversion not being particularly well done and the use of poor quality materials. The current owners are doing a sterling job bringing here back to life. (see YouTube Ship Happens). They are finding that most of the 80 year old woodwork is in great condition and any rot they are repairing was caused by the 80's deck leaking.
My model is for the most part scratch built with the exception of the moulded plastic HDML hull.
I'm quite a long way into the build so will just throw in a load of photos for now.

As you will see from the previous photos the deckhead/upper deck is wider than the cabin and extends right out to the full beam width forming a covered passageway alongside the cabin which is all well and good but makes it very difficult/impossible to access the inner workings of the model. The real Sarinda has 3 supports down each side attaching upper deck to the bulwarks.
To resolve this I am attaching the upper decks to the cabin but not attaching them to the supports. I plan for the supports to have pegs in the top which will register into the deckhead. We will see how that pans out.

Coming together. trying to find the balance between strength and not adding too much weight up top. The forward part of the Deckhead gets progressively thicker in an upwards curve plus the front is rounded so not an easy task.

Balsa blocks to help form the window shapes and angles. The windows lean forward at the top so each window is a different shape.
Had to build a mini router table with my Dremel type tool plus break out the magnifier as the window jambs are only 2.5mm.

So this model is about 36" long which makes these windows about an inch square. the cabin side windows will be even larger. I don't plan to do any interior so don't want the windows and portholes to be see through.

So the question is what to use to blank these off?

I have to hand some semi matt plasticard or some car window tint material.

Any other suggestions?

Progress on the wheelhouse which will be fitted to the foredeck as the main cabin and deckhead will be removable and will simply sit down on top of it as can be seen in the last photo.

Easily the most difficult part of the build so far. Built from 0.5 & 1mm plasticard. Lots of CAD (Cardboard Aided Design) for all the curved pieces