Have WDS got anything suitable?
What does the other side of the brush holder clamp look like ? Are you hoping for a brush head as well ?
Which bit do you want? The brush, the clamp or the bracket?
From your comments about the router brush, I assume it's the brush you want. This any good?
I searched 'brush strip' on google, seems to be plenty of suppliers, bristle lengths, thicknesses etc
look at door brush @knighty






