Replaced the black roofing on the front and rear of my Korber Roundhouse with clear acrylic and added three chimneys on the rear.
Looks like there's nothing there (but you can see the "floating" chimneys if you look close), so it must have come out well !!
BTW, for anyone interested, the gray foam roadbed used by GRJ also comes in widths for Fastrack and it looks good in that application as well.