I watched another video last night and even though it was from the end of the steam era, the tunnels shown did not have the smoke finger prints.
I cannot figure out how some of the old portals don't show the smoke tell-tale. As David said: "I know darn well that one at Harpers Ferry had black on it at one time." Maybe they were washed; other than rain, that is?
I am going to finish the two that I am making now and place them on the layout without the smoke marks, and see how they look. I can always add the smoke later on rather easily.
The problem is that these two are in close vicinity to several others that already have the smoke added, and the new ones may look out of place.
Thanks for your thoughts!
Alex
