well the gearbox is now back in and I replaced the clutch/arm/release and spigot bearings, I also reinforced the clutch arm with a piece of steel welded to the inside of the recessed part of the arm, welded a washer over the area of the pivot point and welded another full piece over the top to the full profile. That should do it..

....the noise was coming from....the springs in the clutch friction plate, they were loose and rattling about...

.....the release bearing was dry as well. Looked like the gearbox had not been out before.....the vehicle had done 80,000 miles and there was still a couple of thousand miles of wear left on the friction plate.
Thanks again to all who took the time and trouble to post with advice.... :D