So, Chris, do you think this was a rolled roofing material, or a liquified rubber substance that was painted on with mineral grit added to the mixture (like later used on metal freight car roofs)??
The phrase "easy to lay" suggests a rolled material, but I cannot make out seams in the photo. For modeling purposes, would one use a single sheet of 400 grit black sandpaper or strips?
Jim Courtney
Poulsbo, WA