Love the blue/black ebonite. sounds like you have a few potential customers lining up...
Wow...I love the idea of an Ebonite handle shaving brush. Ebonite feels great in the hand...much more "organic" than acrylic or other plastics.
My only question is how the Ebonite (hard rubber) will stand up to hot water and soaps.... It's "common knowledge" among the pen collecting community that prolonged exposure to water (particularly hot water) can cause damage and discoloration to Ebonite pens. Also, sunlight can cause color shifts. Maybe there's a reason that early shaving brushes didn't have Ebonite handles? Have you had any real-time experience with using this material in a shaving brush?
The M&F group buy was a good experience for the buyers too, Ken. You handled a complicated project with us prima donnas with competence and even good humor. I'd certainly welcome the chance to do business with you again.
+1 on the question of what knots you would use, though.
One word......WOWSERS