The fore-end cap could depend on what year the hammer gun was made. But the odds are the material used on fore-end cap was hard rubber, like the butt plates. When this hard rubber material was introduced early in Clabrough's career he embraced it and used it extensively,
the higher grades had more detail designs. I had one fall off on a medium grade Clabrough while shooting skeet. Some times with wood shrinkage and age the recoil will dislodge it. I am the author of the Clabrough book Daryl Hallquist referred to in a previous PM. I would like to add this gun to my spread sheet study. If you look at my web site Clabrough.com their is a form for information I'm looking for.