The roof needs to be removable, so that I can get to the electronics if necessary.   I started by making a frame.

Then I used strips of styrene to “plank” it.  The strips allow the plastic to easily follow the curve of the roof.

Next, I start on the roof details.

I wanted some radiator looking bits on top, so I built these out of some brass rod and styrene.

Here’s everything temporarily in place.

Left to right:

• Air cleaner covers the access for the power and volume switch
• Mufflers and smokestacks
• Radiators with fan in between.

Another view of the roof detail.