Grinding noise from handbrake area

Any help would be very appreciated
I towed my mates 90 home a few weeks ago to restore it and when I went around a corner I could hear a horrible grinding noise, it sounded like metal on metal . After a few minutes it stopped. It then started again as I went around another corner.

I have now sorted all the other issues but when I took it for a test drive the noise returned. I have disconnected the rear prop and took it for a drive and the noise is still there. The other issue is the clutch pedal stays down on occasions but not all the time.

I have had the handbrake off and oil has leaked everywhere so I have ordered a new seal but I don't know what is causing the grinding noise or clutch to stay down. The slave cylinder was a new one so assume that's ok

Any ideas ?

have you tried checking the rear output bearing
look at the rod in the top of pedal box it can jam

Thanks will look over weekend. I had thought about rear output bearing but I can't understand why it was intermittent when towing home.