To reproduce them, I made a 2-parts mold.
The walls are made of lego. The walls are made of lego.
Chimneys are from a model kit tree... and the 2 viper! Chimneys are from a model kit tree... and the 2 viper!

and here is a fresh whole squadron. and here is a fresh whole squadron.

After a good cleaning and preparation session, they are painted.

The squadron drying after a black wash.